Operation Arno-Linie

Arno Line

The 'Arno-Linie' was a German defence line in Italy, centred on Florence, which lay just behind the line, and extending westward to the Tyrrhenian Sea near Pisa and eastward to Ribbiena in the Apennine mountains (summer/autumn 1944).

This line was the final obstacle between Lieutenant General Mark W. Clark’s US 5th Army and the 'Gotisch-Linie' defences that were the last major German defences in northern Italy, and was broken in the 5th Army’s western counterpart of the eastern 'Olive' by Lieutenant General Sir Oliver Leese’s British 8th Army. The breaking of the 'Arno-Linie' defences on the western side of Italy was a prerequisite of the 5th Army’s approach to the 'Gotisch-Linie' defences which lay some 20 miles (32 km) farther to the north, and the plans for the British and US forces to reach the 'Gotisch-Linie' defences were, naturally enough, developed in concert but at the same time that 'Dragoon' (i) was being launched in the south of France.

General Sir Henry Maitland Wilson and General the Hon. Sir Harold Alexander, Allied commander-in-chief in the Mediterranean theatre and commander-in-chief of the Allied Armies in Italy respectively, were at this time considering the German positions that lay ahead of the Allies in the Apennine mountains. In a little more than nine weeks, the Allied forces had advanced from the Garigliano river to the Arno river, a crow’s flight distance 270 miles (435 km). One of the major factors faced by the two commanders-in-chief, together with their subordinate army and corps commanders, was the time of year, with the days shortening and the weather becoming steadily more inclement, and this militated in favour of the start of offensive operations at the earliest possible moment.

The fact that his forces had fought to determinedly to hold the 'Albert-Stellung' defences flanking Lake Trasimeno, as well as those farther north in front of Arezzo and Siena, suggested that Generalfeldmarschall Albert Kesselring, the Oberbefehlshaber 'Süd' and commander-in-chief of Heeresgruppe 'C' in Italy, needed additional time to strengthen the 'Gotisch-Linie', which was the most northerly position which could be created to exploit the terrain advantages offered by the Apennine mountains. In the west, the approaches to La Spezia were well protected by defences in depth that reached back to Carrara on the coast. Across the mountains, major positions had been prepared astride the routes leading to the Po river valley at Borgo a Mozzano, Porretta to the north of Pistoia, the Vernio pass to the north of Prato, and the Futa and Il Giogo passes to the north of Florence. The line then changed direction to the south-east, extending from Casaglia via San Godenzo and Sevravalie to Valsavignone, with each route running through the mountains again covered by strongpoints. The line now turned east and followed the Foglia river to Pesaro. This last sector, covered only by low foothills, had been well developed with anti-tank ditches, large minefields and complexes of sturdy bunkers and dug-in tank turrets. On this flank the coastal defences extended as far to the north as Ravenna.

The southern face of the Apennine mountains opposing the Allies rose sharply to high peaks but once the watershed was crossed the ground fell quite gradually down toward the valley of the Po river. Alexander considered that the least difficult of the routes available to his forces were those through the Vernio and Futa passes linking Florence and Bologna. All the roads through these passes, however, were very vulnerable to demolition at the points where they had been artificially constructed, by cutting into the sides of the valleys, to avoid the highest parts of the passes, which were snowbound in winter.

Kesselring’s defensive positions on the 'Gotisch-Linie' were some 200 miles (320 km) long from the coast of the Tyrrhenian Sea in the west to the coast of the Adriatic Sea in the east, and all but the final 55 miles (90 km) at the eastern end were difficult mountainous terrain with the advantage resting with the defence. The major work of creating the major strongpoints was now nearly complete, and the primary task still needing work by the German engineers was the completion of the linking positions, which had already been sited, to create a continuous front.

The only south/north main road bypassing the Apennine mountains was Highway 16 on the Adriatic coast but, though flat, this route along the narrow coastal plain was by no means well suited to military operations as low foothills, as well as many rivers and streams all liable to sudden flooding, cross the plain at right angles to the necessary axis of advance. Moreover, the area was similar to that which had proved so difficult farther to the south in the region of the Sangro river, with heavy soil which quickly turned to cloying mud after rain. To the north of the narrow gap between the mountains and the sea at Rimini, the coastal plain widens quickly but the Romagna region’s soft ground is broken by a number of broad but embanked rivers flowing generally to the north-east: some of the flood banks were 40 ft (12 m) high.

On the northern side of the Apennine mountains, Highway 9 passed close below the mountains from Rimini right through Modena to Pavia, giving the Germans good communications for the lateral movement of their reserve formations.

During August Kesselring inspected much of the 'Gotisch-Linie' defences and expressed himself well satisfied. A German report of a time early in September listed the fact that the defences contained 2,376 machine gun posts, 479 anti-tank gun, mortar and assault gun positions, 75 miles (120 km) of wire entanglements, and considerable lengths of anti-tank ditch, but also pointed out the fact that only four of the planned total of 30 88-mm (3.465-in) PzKpfw V Panther medium tank gun turrets had been sited in their static emplacements.

The balance of forces at about the time the battle for the 'Gotisch-Linie' began with the British in the east and the Americans in the west, the latter having first to break though the 'Arno-Linie' defences, was 26 German divisions including six Panzer and Panzergrenadier divisions, and some six divisions of Benito Mussolini’s revived Fascist Italian state, against 21 Allied divisions including four armoured divisions. As the Axis air strength in Italy had been reduced to just 120 German aircraft (40 single-seat fighters, 45 reconnaissance aircraft and 35 wholly obsolete Junkers Ju 87 single-engined dive-bombers) and 50 Italian single-seat fighters, the Allies had the benefit of complete superiority in the air.

The Allied original plan to break though the 'Gotisch-Linie' defences had been schemed on the basis of a concentrated drive by four corps (totalling 14 divisions) in the centre on the axis from Florence to Bologna, and was posited on the availability of sufficient Allied strength on the two flanks to pin Kesselring’s flanking formations and so prevent their lateral movement to support the Axis forces operating in the centre of the front. But now, with some of his forces diverted to other theatres, Alexander lacked the resources to achieve this plan and therefore proposed to move the main weight of the attack by nine divisions to the Adriatic flank, aiming initially through the narrow gap at Rimini in 'Olive'. A secondary attack by five divisions would follow within the week through the central mountains toward Bologna, on which both attacks would converge. As before, holding forces would be required on the left flank, but the Allied right flank would be protected by the Adriatic Sea.

This new plan resulted largely from the concern, primarily of Leese but also of Alexander, that the 8th Army would be better used on the Adriatic coastal plain as it lacked mountain divisions and pack transport, and also had little experience in mountain warfare. On the coastal plain the 8th Army should be able to exploit its superiority in armour and artillery, but only in the event that the attack had made significant progress before the advent of the autumn rains. The plan was agreed at a meeting between Wilson, Alexander and Lieutenant General Sir Allan (John) Harding, Alexander’s chief-of-staff, and the preparations were carried out in the greatest secrecy, with no written orders issued until a time immediately before the launch of the offensive on 25 August.

During its advance toward the 'Arno-Linie' defences, the 5th Army had been supplied from the dumps at Anzio and through the ports of Civitavecchia, Piombino and finally Livorno, while the 8th Army had been reliant on supplies forwarded by road and rail as far as Arezzo, where a railhead was finally formed. To help during the advance the Americans had agreed to a limited tonnage being landed at Piombino for the 8th Army, and in the middle of July Ancona on the Adriatic flank was captured, offering additional capacity of a limited nature. The switch of the main strength of the 8th Army to the Adriatic sector now required the use of both Arezzo and Ancona, and urgent steps were taken to develop Ancona’s port facilities. The 5th Army, which included a major British component, continued to be supplied through the ports of the Tyrrhenian Sea coast. Livorno was taken on 19 July, and salvage and repair ships arrived eight days later. The dock area was heavily mined and booby-trapped, the quays were cratered, and the harbour’s entrance was almost completely blocked by sunken ships. Although it remained under long-range artillery fire for some weeks to come, the harbour of Livorno was opened for Allied business on 26 August, and soon became the main supply port for the 5th Army.

The eastward move across the Apennine mountains of the equivalent of eight divisions, two corps headquarters and numerous corps troops required the use of about 80,000 vehicles. Only two mountain roads, each mainly of the single-track type, were available. Both had been the subjects of extensive demolitions, and in addition to considerable reconstruction work the Royal Engineers had to build 40 Bailey bridges before the roads could be opened. The army’s movement staff set up a special headquarters at Foligno, and the move was completed in about 15 days.

The only reinforcements available for the 5th Army’s operation to break through the 'Arno-Linie' defences were a regimental combat team of Major General Edward M. Almond’s US 92nd Division, which went into reserve in the area of Major General Lucian K. Truscott’s US VI Corps, and one infantry regiment of the Brazilian Expeditionary Force. Major General Vernon E. Prichard’s US 1st Armored Division, which was one-third under strength and needed reorganisation, also remained in reserve.

The original cover plan, which had already been put into operation, had been designed to draw the Germans away from the centre of the 'Gotisch-Linie' positions. Now the 5th Army was instructed to prepare an ostensible assault for a major attack in this area, and so suggesting to the Germans that the 8th Army’s attack in the direction of Rimini was merely a feint.

Meanwhile the German order of battle had undergone significant change: Generalleutnant Wilhelm Schmalz’s 1st Fallschirmpanzerdivision 'Hermann Göring' had been relocated to East Prussia and replaced by Generalleutnant Alfred Reinhardt’s 98th Division from Zagreb, and Generalmajor Kurt Cuno’s 3rd Panzergrenadierdivision and Generalmajor Ernst Günther Baade’s 15th Panzergrenadierdivision had be diverted to the Western Front in France, and were not replaced in Italy until September.

Intelligence reports about the Allied preparations for 'Dragoon' (i) had led Kesselring to fear that the Allied target area would not be southern France but rather the Ligurian coast of north-western Italy, and he therefore moved Generalleutnant Gerhard Graf von Schwerin-Krosigk’s 90th Panzergrenadierdivision first to Genoa and then, after the 'Dragoon' (i) landing had taken place, to the Franco-Italian frontier to join Generalleutnant Theobald Lieb’s 34th Division. Here the two formations were reinforced by Generalleutnant Otto Fretter-Pico’s 148th Division and Generalleutnant Paul Schricker’s 157th Gebirgsdivision, which had fallen back on the Maritime Alps after being pinched out by the rapid French and US advance into the valley of the Rhône river.

Guarding the coast of the Italian riviera between La Spezia and Savona were Generalleutnant Walter Jost’s 42nd Jägerdivision and two Italian divisions.

At the head of the Adriatic Kesselring retained Generalleutnant Bernhard Steinmetz’s 94th Division in the area of Udine and Generalleutnant Wilhelm von Hösslin’s 188th Reserve-Gebirgsdivision in Istria.

The rest of Kesselring’s strength, some 19 divisions in all, was deployed on and forward of the 'Gotisch-Linie' defences. Generaloberst Heinrich-Gottfried von Vietinghoff-Scheel’s 10th Army held the eastern sector. General Traugott Herr’s LXXVI Panzerkorps was in the coastal sector with Generalleutnant Harry Hoppe’s 278th Division and Generalleutnant Wilhelm Raapke’s 71st Division (both radically under strength) and Generalleutnant Dr Julius Ringel’s 5th Gebirgsdivision in the line as far as San Sepolcro; Generalmajor Hans Korte’s 1st Fallschirmjägerdivision and Generalleutnant Ralph von Heygendorff’s 162nd Division (turkestanische) were echeloned back in reserve and covering the coast. General Valentin Feurstein’s LI Gebirgskorps held the line as far as the boundary between the two German armies, just to the west of Pontassieve. This mountain sector was held by Generalmajor Hans-Joachim Ehlert’s 114th Jägerdivision, Generalleutnant Heinrich Deboi’s 44th Division, Generalleutnant Friedrich-Wilhelm Hauck’s 305th Division, Generalleutnant Hellmuth Böhlke’s 334th Division and Generalmajor Hanns von Rohr’s 715th Division. In army reserve near Bologna was Generalleutnant Alfred Reinhardt’s recently arrived 98th Division.

General Joachim Lemelsen’s 14th Army held the front from Pontassieve across to the coast on the western flank with eight divisions. The central sector was held by General Alfred Schlemm’s I Fallschirmkorps, which comprised Generalleutnant Karl Faulenbach’s 356th Division, Generalleutnant Heinrich Trettner’s 4th Fallschirmjägerdivision and Generalleutnant Heinrich Greiner’s 362nd Division. General Fridolin Ritter und Edler von Senger und Etterlin’s XIV Panzerkorps, which comprised Generalleutnant Eduard Crasemann’s 26th Panzerdivision, Generalleutnant Gustav Heistermann von Ziehlberg’s 65th Division and SS-Obergruppenführer und General der Waffen-SS Max Simon’s 16th SS Panzergrenadierdivision 'Reichsführer-SS', held the line between Empoli and the Tyrrhenian Sea. In army reserve were Generalmajor Fritz Polack’s 29th Panzergrenadierdivision to the north of Florence and Generalmajor Wilhelm Crisolli’s 20th Felddivision (L) near Viareggio.

This disposition revealed Kesselring’s continued preoccupation with the central sector as two of the three reserve divisions, including the only mobile reserve formation, were located between Florence and Bologna in the section of the Apennine mountains which is narrowest, at just 50 miles (80 km), but with peaks rising to 6,500 ft (1980 m), about twice as high as in the narrow range of the 'Winter-Linie' defences that had stalled the Allies some nine months previously.

During the night of 10/11 August the Germans pulled back to the outskirts of Florence, and on the Adriatic coast Lieutenant General Władysław Anders’s Polish II Corps pressed forward to clear the high ground between the Cesano and Metauro rivers. By 23 August the Poles held the right bank of the Metauro for some 15 miles (24 km) inland and were within about 12 miles (20 km) of the main 'Gotisch-Linie' positions.

Along the 'Arno-Linie' area, however, the Germans still stood well forward of the 'Gotisch-Linie' defences. With as much of his strength as possible concentrated on the right flank, Alexander was now ready to strike at Pesaro. The Polish II Corps was holding a front of 7 miles (11.25 km), and its sole task was the seizure of the high ground to the north-west of Pesaro. Lieutenant General E. L. M. Burns’s Canadian I Corps (Major General H. W. Foster’s 1st Division, Major General B. M. Hoffmeister’s 5th Armoured Division and Brigadier D. Dawnay’s British 21st Army Tank Brigade) was concentrated on a front of only 2 miles (3.2 km) screened by the Polish troops, and its task was to gain the high ground to the west of Pesaro, make for Highway 16 and attack toward Rimini.

Lieutenant General C. F. Keightley’s British V Corps, considerably strengthened and now comprising Major General R. A. Hull’s 1st Armoured Division (plus single armoured and tank brigades) together with Major General A. D. Ward’s 4th Division, Major General A. W. W. Holworthy’s Indian 4th Division, Major General J. L. I. Hawkesworth’s 46th Division and Major General J. Y. Whitfield’s 56th Division, was disposed on a 20-mile (32-km) front ready to advance on an axis west of Rimini toward Bologna and Ferrara.

The remainder of the 8th Army’s front, right across to the high Pratomagno range mid-way between Florence and Arezzo, was lightly held by Lieutenant General Sir Richard McCreery’s British X Corps with Major General D. W. Reid’s 10th Division, one armoured brigade and several dismounted armoured car regiments, supplemented by some infantry. In army reserve was Major General C. E. Weir’s New Zealand 2nd Division soon to be supplemented by a Greek mountain brigade from the Middle East in the area around Iesi.

Lieutenant General S. C. Kirkman’s British XIII Corps had now joined the 5th Army and held the sector from the Pratomagno range to a point just west of Florence with Major General H. Murray’s 6th Armoured Division, Major General D. Russell’s Indian 8th Division and Major General C. F. Loewen’s 1st Division, with a Canadian armoured brigade in support.

On the left of the XIII Corps was Major General Geoffrey T. Keyes’s US II Corps , which was screened by the 442nd RCT holding a 4-mile (6.4-km) front. The II Corps comprised Major General Charles L. Bolte’s 34th Division, Major General John E. Sloan’s 88th Division and Major General William G. Livesay’s 91st Division, each with tank support, and was held ready to deliver the second blow of Alexander’s planned 'two-handed punch' toward Bologna, to be followed by an attack by the XIII Corps toward Imola.

The remainder of the 5th Army’s front was held by Major General Willis D. Crittenberger’s US IV Corps with Major General W. H. E. Poole’s South African 6th Armoured Division, Prichard’s 1st Armored Division, Major General John B. Coulter’s 85th Division, part of Almond’s 92nd Division and Task Force 45. This last, of about divisional strength, had been formed in a matter of weeks from US anti-aircraft, anti-tank and reconnaissance units, now deemed surplus to requirement in their original roles, supplemented by the units of a British anti-aircraft brigade. After a very short period of infantry training Task Force 45 achieved excellent results in holding extensive defensive positions.

The Japanese-American 442nd Infantry was withdrawn on 3 September and sent to join Lieutenant General Alexander McC. Patch’s US 7th Army in France.

At 23.00 on 25 August the Polish II Corps, together with the Canadian 1st Division and 46th Division, moved forward. The attack opened in silence but within an hour an artillery barrage was laid down to cover the crossing of the Metauro river. By dawn five divisions were advancing well beyond the river against only weak resistance.

Once again Kesselring had been taken completely by surprise by the 8th Army’s cleverly concealed concentration. The LXXVI Panzerkorps had in fact been caught in the middle of a regrouping: in order to relieve the 90th Panzergrenadier Division on the Italian/French frontier with the 5th Gebirgsdivision, the 278th Division was being withdrawn through the 1st Fallschirmjägerdivision to fill the gap on the corps' right flank. The Germans were thus already moving back on the coastal sector and mistook the Polish attack for a normal follow-up to retain contact. Another three days passed before Lemelsen fully appreciated that he had been mistaken about the strength of the assault, and on 30 August both the V Corps and Canadian I Corps had crossed the Foglia river into the advance positions of the 'Gotisch-Linie' proper. In the combat of the following two days, the 8th Army achieved a further penetration along a 20-mile (32-km) front inland from the coast, and the 1st Fallschirmjägerdivision, which had suffered 50% casualties, scarcely avoided encirclement in its withdrawal to the line of the Conca river.

By 29 August a regiment of the 26th Panzerdivision was in action on the Foglia river and the remainder of the division, as well as the 98th Division, was rushed forward in an effort to halt the Allied advance. The 26th Panzerdivision was committed only in small packets, however, and both divisions suffered heavy losses.

By 2 September the Canadians had crossed the Conca river, and the British V Corps' two armoured divisions were about to be committed toward Rimini and beyond. Kesselring now committed his last mobile reserve, the 29th Panzergrenadierdivision from Bologna.

Between the advance of the two Allied corps was the town of Coriano, high on a ridge which was to be the scene of some of the bitterest fighting of the whole Italian campaign. Here and at Geminano, some 5 miles (8 km) to the south, were now assembled the 1st Fallschirmjägerdivision, 26th Panzerdivision and 29th Panzergrenadierdivision, and in the 4/12 September period these held their ground against all Allied attacks. Quite unexpectedly, heavy rain fell for three days at the start of this vital stand. The advancing Allied tanks and guns and vehicles were quickly bogged down and air support was seriously limited.

The impetus of the 8th Army’s attack had now been lost, and Alexander knew that it was time to switch the weight of the Allied offensive to another sector.

As the battle developed and his reserves were committed, Kesselring soon realised that he could only hope to build another reserve by pulling back to the well-prepared defences of the 'Gotisch-Linie' along the rest of the front. On 30 August, therefore, the LI Gebirgskorps began to fall back, with the British X Corps following it. On the extreme right of the German line the XIV Corps also fell back on to the main positions of the 'Gotisch-Linie', allowing the IV Corps to reach Lucca on 6 August and Pistoia on 12 August.

The I Fallschirmkorps had good intermediate positions in the mountain immediately to the north of Florence, however, and occupied these on 3 September. This forward deployment was probably intended to buy the time for Kesselring to adjust the boundary between the 10th Army and 14th Army, and to create the reserves which were now needed as a matter of urgency. The 20th Felddivision (L) from the XIV Corps and a regimental-size Kampfgruppe of the 90th Panzergrenadierdivision were transferred to reinforce the Adriatic sector, and the 356th Division was taken from the I Fallschirmkorps as a further reserve on this flank.

A major Allied breakthrough in the Adriatic sector would have threatened the line of withdrawal north-east for the whole of Kesselring’s remaining forces. While full knowledge of these moves was still denied to Allied intelligence, Alexander now deemed that the time was right for the 5th Army to go over to the offensive. Clark’s plan was for the XIII Corps to use its Indian 8th Division for the seizure of the line of hills from Monte Morello to Monte Giovi, which covered the exits from Florence. The US II Corps would then advance through the XIII Corps' sector and attack straight toward Firenzuola with all four of its divisions, and at the same time the XIII Corps would advance on Faenza and Forlì.

The task of the IV Corps was to exert the maximum possible pressure of the Germans while the 1st Armored Division came into army reserve ready to exploit any breakthrough.

The 5th Army’s plans had been completed by 8 September, but on this day the Germans began to withdraw from their forward positions in he area to the north of Florence. The US II Corps' 91st and 34th Divisions followed this withdrawal astride Highway 65 and pressed the Germans back so successfully that by 12 September the strong positions on Monte Calvi had fallen and the Americans were hard up against the main 'Gotisch-Linie' positions at the strongly fortified position covering the Futa pass.

Both Allied armies were now ready to resume the offensive. Attacking side-by-side on the night of 12/13 September, the I Corps and V Corps reached the crest of the Coriano ridge, taking 1,000 prisoners on the first day. Geminano fell to the Indian 4th Division on 15 September, by which date the Canadians were across the Marano river and the Indian 4th Division had reached San Patrignano with the 1st Armoured Division on its left, and the 46th Division was through Montescudo. The New Zealand 2nd Division was now moved forward in preparation for passing through the I Corps, which was meanwhile engaged in a bitter fight for San Fortunato, a key position on a ridge some 3 miles (4.8 km) from Rimini. The fight for San Fortunato continued for three days until the town was finally cleared on 20 September, and the same night the Greek mountain brigade entered Rimini. This brigade, which fought well in its first engagement, was the only reinforcement that the 8th Army had received in response to Wilson’s urgent requests for reinforcements to the Combined Chiefs-of-Staff in July and early August.

The weather now intervened, and under cover of torrential rain, the Germans withdrew overnight across the Marecchia river. On the following day Allied patrols also crossed this river. Ahead lay the coastal plain, but across the line of advance the rivers were filling with the rain water pouring down from the mountains, and under foot the heavy soil was starting to grip men and vehicles as they struggled forward through the narrow coastal strip below the mountains where the 5th Army’s offensive had already started.

During the night of 21/22 September the New Zealand 2nd Division took over from the Canadians and advanced to the north along Highway 16 until checked by strong opposition on 25/26 September along the line of the Uso river, and again by heavy counterattacks on 29 September on the line of the Fiumicino river. At this point the New Zealanders' advance was held up by heavy rain.

On the New Zealanders' left, the 5th Armoured Division had also reached the Fiumicino against increasing resistance, but was driven back from its small bridgehead on 29 September.

The V Corps was now struggling forward across the line of foothills farther inland, and making only somewhat slower progress. On the edge of the plain the 56th Division, which had been in action for three weeks without a break, paused on 22 September to regroup. Meanwhile the Gurkhas of Brigadier A. R. Barker’s Indian 43rd Brigade (Lorried) took the heavily mined and booby-trapped village of Santarcangelo on the Uso river, which was the key to a stop line running to the south-west toward Montebello. The 56th Division now relieved the 1st Armoured Division, and by 27 September reached the Fiumicino river on each side of Savignano, and by 29 September the eastern bank of the river in the plain had been cleared. The Germans were still holding out in the foothills south of Highway 9, however.

Four days of torrential rain now made off-road vehicle movement wholly impossible. The fords through the Marecchia and Uso rivers became impassable, and five bridges over the Marecchia river were swept away. The Fiumicino river swelled to a width of 30 ft (9.1 m), and the speed and depth of the water made it impossible for infantry patrols to cross. The V Corps fought its way forward, but it was nearly one week before the 46th Division on the left reached the Fiumicino river.

Between the two Allied armies the X Corps pressed a German withdrawal up highway 71, and after a comparatively small but intense fight for the Mandrioli pass on 24 September crossed the watershed. The advance of the Indian 10th Division on the long descent toward Cesena was halted by four days of heavy rain, however, and the armoured brigade was now switched to the Adriatic sector, being replaced by Brigadier C. A. M. D. Scott’s British 1st Guards Brigade Group reinforced by the British anti-aircraft brigade from the 5th Army fighting as infantry.

By 6 October the X Corps had penetrated to within some 15 miles (24 km) of Cesena.

The 5th Army’s offensive began on 13 September even as the 8th Army launched its attack on Coriano. Clark’s plan was to strike first at the Il Giogo pass and through to the upper reaches of the Santerno river valley to outflank the major defences on Highway 65 at the Futa pass. A preliminary attack to hide this intention would be made astride Highway 65 by the 34th Division. The main thrust would then come from the 85th and 91st Divisions against German positions on the peaks guarding the Il Giogo pass from east and west respectively. The 88th Division was ready to exploit any success, and the left flank of the attack’s leading edge was to be protected by the South African 6th Armoured Division. The task of the XIII Corps was to attack into the mountains and protect the right flank of the US offensive. The 1st Division was to move forward on the axis from Borgo San Lorenzo toward Faenza with the Indian 8th Division on its right in the direction of Marradi, while Major General G. W. R. Templer’s British 6th Armoured Division was to advance from Dicomano toward Forlì.

This combined British and US thrust straddled the boundary between the 10th Army and the 14th Army, a line extending from Imola to a point east of the Il Giogo pass.

The attack of the US II Corps thus fell entirely on the 4th Fallschirmjägerdivision and that of the XIII Corps on the 715th Division and the flank of the 305th Division. After two days of heavy fighting, the US II Corps' attack had made little progress. On the highest part of the mountain range and east of the pass were the peaks of Monte Prefetto with Monte Pratone and Monte Verruca beyond it, and Monte Altuzza past them and overlooking the Il Giogo pass. In this area the XIII Corps had more success, on 14 September the Indian 8th Division crossed the watershed, and on the following day the 1st Division captured Monte Prefetto and started an attack toward Monte Pratone. The 85th Division now assumed responsibility for the attack on Pratone, but was halted some 1,000 yards (915 m) short of this objective. During the following night a battalion of the 85th Division reached Monte Altuzza and throughout 17 September fought off determined German counterattacks. By that evening several other strongpoints and peaks had been captured, and when the US 91st Division took Monte Montecelli on 17/18 September, the US II Corps was holding a 7-mile (11.25-km) stretch of the 'Gotisch-Linie' on either side of the Il Giogo pass.

To block this gap Kesselring ordered the 362nd Division across to cover Firenzuola and the 44th Division was brought up from the LI Gebirgskorps to cover the road from Firenzuola to Imola. This sector was critical to the German defence as it was one of the few areas in which artillery and transport could be deployed once they had crossed the watershed: elsewhere the terrain, falling gradually toward the north-east, was broken by rivers running in deep gorges and in general was rocky and often steep, while the long mountain spurs extending toward the plains below contained many isolated peaks which dominated the few and inadequate routes descending slowly toward Highway 9.

Clark now decided to develop the 5th Army’s exploitation along the road to Imola. On 21 September the 85th Division captured Firenzuola and the strongly held position of Monte la Fine, while east of the Imola road the 88th Division, advanced across very difficult terrain to take Monte la Battaglia, a mountain mass dominating the valleys of the Senio and Santerno rivers, on 27 September. The attack had now reached a point only 10 miles (16 km) from Imola itself.

By this time the Germans were counterattacking strongly with elements of four divisions, and this effort now halted the Allied advance. On the 5th Army’s right flank, the XIII Corps had taken San Benedetto and Marradi on 24 September but, in the face of mounting German resistance, could move forward no farther.

On the left of the US II Corps, the 91st Division had forced a passage of the Futa pass by taking the dominating height of Monte Gazzaro, and by 28 September had reached the Radicosa pass. The 34th Division had meanwhile advanced on the parallel road leading to Bologna and reached a point just short of Castiglione dei Pepole when it was replaced by the South African 6th Armoured Division. To the west, the Allied line now ran from 5 miles (8 km) north of Pistoia over the mountains to a point near Massa on the coast.

In the last days of September the Germans abandoned the few remaining prepared 'Gotisch-Linie' positions except those along the Ligurian coast. As had been expected, the major advance had been by the 8th Army, where a penetration of 30 miles (48 km) had been achieved in 26 days. On the Adriatic flank the 8th Army was faced with about 12 river lines running directly across its axis of advance to the Romagna district. The autumn rain, which were heavy as well as early, had brought tracked as well as wheeled vehicles to a complete halt everywhere except the few roads. Former swamp land reclaimed and cultivated over centuries, this area quickly became covered with the stickiest mud encountered in the whole of the Italian campaign. With the rivers in spate and a succession of violent rainstorms at the end of September, the chance of any breakthrough in this area had gone, but in spite of the deteriorating weather and the growing exhaustion of the 5th Army there still seemed to be at least a chance of breaking clear of the mountains in the central sector up Highway 65 to Bologna.

Major General R. K. Arbuthnott’s British 78th Division had just arrived from Egypt and on 2 October was sent to reinforce the XIII Corps. Alexander now issued orders for the renewal of the offensive. The 5th Army’s offensive in the direction of Bologna would start on 1 October, and the 8th Army’s attack to the north and parallel with the road linking Rimini and Bologna would be launched by the I Corps and V Corps on the night of 6/7 October. Leese had been given the command of the Allied Land Forces South-East Asia and was succeeded on 1 October by McCreery. Having had recent experience in the mountains where his X Corps had linked the two Allied armies, McCreery felt that the high ground was less of a barrier than the waterlogged plains.

An attack by the Indian 10th Division over the foothills succeeded in expanding a bridgehead over the Fiumicino river, and Monte Farneto, just 8 miles (13 km) to the south of Cesena, was taken on 7 October. The main attack north of Highway 9 was nonetheless still checked by continued storms characterised by very heavy rain.

Kesselring reacted immediately to the advance through the mountains and ordered the 29th Panzergrenadierdivision from the area north of Highway 9 to protect Cesena, but by 14 October the division had been withdrawn to help halt the 5th Army’s attack on Bologna.

In the meantime the 8th Army’s main attack had started, and on 16 October reached the line of the Pisciatello river. On the next day the Polish II Corps attacked through the mountains on the left of the V Corps in the direction of Rocca San Casciano with the object of opening communications with the 5th Army on Highway 67. By 21 October both Galeata and Strada had been taken against stiffening resistance, and by 20 October Cesena had been entered and bridgeheads seized over much of the Savio river except its course in the plain, where the Germans still held Cervia on the coast.

The Polish II Corps now headed toward Forlì and the British V Corps attacked from its Cesena bridgeheads. The Germans held for four days before pulling back to Ronco river. By this time the LXXVI Panzerkorps had withdrawn the 29th Panzergrenadierdivision, 90th Panzergrenadierdivision and 1st Fallschirmjägerdivision to reinforce the central sector, where the situation opposite Bologna was critical, so Herr had to shorten his line in the foothills opposite the 8th Army.

By this time the weather had broken completely and, in combination with von Vietinghoff-Scheel''s dogged determination, this was sufficient to halt both the Allied armies. After the 88th Division had been checked only 10 miles (16 km) from Imola, the German defensive line covering Highway 65 was pulled back to the village of Monghidoro on high ground astride the road. Behind this position streams, separated by ridge lines, drained northward on both sides of the road.

The Americans were now 24 miles (39 km) from Bologna but separated from this major city objective by three excellent defensive positions at Loiano, Livergnano and Pianoro in the last 15 miles (24 km) of mountainous country. From the US forces' point of view, the road communications were so limited that it was impossible to relieve divisions if the attack was made on a narrow front and Clark decided to advance with four divisions in line, each with two regiments up and one down in reserve. The plan was to rotate the leading regiments about every five days so that the successive defence lines would be attacked by reasonably fresh or rested troops. The two divisions already in position would lead the attack, with the 91st Division astride Highway 65 and the 85th Division on its right. The left flank would be protected by the 34th Division along the line of the Setta Creek, and the 88th Division would perform a similar task on the right flank after being relieved by the 1st Guards Brigade Group of the XIII Corps on Monte Battaglia and by the British 78th Division on Monte Cappello.

At 06.00 on 1 October the US II Corps' offensive began on a 16-mile (25.75-km) front, and after the early-morning mist had cleared the day was clear and sunny, facilitating both artillery and air support. Opposite Imola the Americans ran into major counterattacks, but along Highway 65 the advance started well. The next day saw the rearrival of fog, low cloud and a cold and driving rain which lasted for seven days. The reduction of the Monghidoro line took four days, the American advance averaging only 1 mile (1.6 km) per day, and in the face of stubborn delaying tactics the US reserve regiments were now brought forward to tackle the German defences in the line of hills behind Loiano. By this time the American tanks and tank destroyers were having great difficulty in getting forward over the muddy and very slippery trails, and the infantry attacks were also greatly hampered by the weather.

There still seemed a good chance that the US II Corps would reach the Po river valley before the rain turned to snow at the end of October, but by now the 16th SS Panzergrenadierdivision was moving east against the 34th Division on the US II Corps' left flank, and there was evidence that the entire 65th Panzergrenadierdivision had also arrived from the XIV Panzerkorps to move into the line beside the 4th Fallschirmjägerdivision and so block the road to Bologna. At the same time the 98th Division, released from the Imola sector, was closing on the 88th Division. These moves brought the German strength opposing the II Corps to five divisions, together with elements of three other divisions, compared with a strength of one full division and elements of two others when the offensive started.

In the period 5/9 October the four US divisions forced their way forward and compelled the Germans to pull back to the Livergnano escarpment. This position had great natural strength, the main barrier being a sheer rock wall some 3 miles (4.8 km) long and in some places nearly 1,475 ft (450 m) high, and with its flanks protected by the deep gorge of the Zena creek to the east and a dominant hill mass to the west. More hill masses lay astride the line of advance east of Highway 65.

The Germans were no longer prepared to give ground, and an attack by the 85th Division was held for three days by elements of no less than four German divisions. In the period 10/15 October the weather improved considerably and, again taken under heavy artillery and air attack, the Germans were forced back from Livergnano, which they evacuated late on 14 October.

The losses of each side had been heavy, but while the US II Corps was finding it acutely difficult to find reinforcements, the Germans seemed to be able still to find the troops to fill the gaps. Elements of the 29th Panzergrenadierdivision had been identified to the north of Livergnano, and the volume of German artillery fire had now doubled since the beginning of the month. Much of the credit for this must go to von Senger und Etterlin who, during the temporary illness of Lemelsen, had been brought in to command the 14th Army on 15 October for about a week. During this time he succeeded in co-ordinating the defensive fire on the vital sector opposite Bologna and moved in further reserves from his own corps. Much of the German artillery was now concentrating on the US supply line up Highway 65, and both here and west of the road the US offensive had now been halted by the determined resistance of the 16th SS Panzergrenadierdivision and 29th Panzergrenadierdivision.

The XIII Corps now assumed responsibility for more ground on the right flank to relieve the 88th Division for an assault on Monte Grande, which had been decided in an attempt to widen the salient east of Highway 65. With the assistance of 158 fighter-bomber sorties and 8,100 rounds of artillery fire, this feature was captured by dawn on 20 October, one full day before its fall had been expected.

The US II Corps' axis of attack was now moved to exploit this success, but by this date the 90th Panzergrenadierdivision and the 1st Fallschirmjägerdivision were in position covering the approaches to Castel San Pietro and Highway 9. The US attempts to take and hold the village of Vedriano on the nights between 22 and 25 October were finally frustrated by German counterattacks. During the afternoon of 26 October, Keyes ordered the 85th and 88th Divisions to dig in on the nearest defensive positions. The 88th Division was halted only 4 miles (6.4 km) from Highway 9 and the 34th Division east of Highway 65 was checked 10 miles (16 km) from the centre of Bologna.

On the following day the entire 5th Army went over to the defensive. The casualties on each side had been very heavy. Decidedly adverse weather conditions, supply problems over inadequate roads and lack of reinforcements all had contributed to the waning of the Allied offensive, especially in the face of the increasingly standard type of stubborn German resistance, effectively prevented the exploitation of Alexander’s success in breaking through the 'Gotisch-Linie' defences. The battle for the 'Gotisch-Linie' had been fought between ground forces of relatively equal strength, but the Allies' complete air superiority had played a great part in deciding the issue.

In the early stages of the battle, while Lieutenant General John C. Cannon’s US 12th AAF was engaged in the support of 'Dragoon' (i), Air Vice Marshal Harry Broadhurst’s Desert Air Force had supported both the 5th and 8th Armies. In fact the Desert Air Force had at this stage already taken over the interdiction programme from the Po river to the south between Pavia and the Adriatic. On 26 August the entire effort of the Desert Air Force was used to support the 8th Army with 664 sorties flown mainly against the defences about Pesaro. Day by day the fighters and fighter-bombers attacked the German batteries, armour concentrations and positions, and also struck at the German communication centres at Cesena and Rimini. By night, Douglas Boston and Martin Baltimore medium bombers struck at communications between Rimini, Ravenna and Bologna. On the last three nights of the month medium bombers of the Strategic Air Forces attacked Pesaro in support of the Polish attack.

As the 7th Army advanced up the Rhône river valley and passed beyond the range of the 12th AAF from its Italian and Corsican bases, its squadrons flying from Corsica switched some of their effort back to Italy and by early September three fighter groups and a medium bomber group were operating in support of Alexander’s offensive. Before Clark’s main attack these groups concentrated on communication targets and particularly the Po river crossings and the rail bridges below Lake Maggiore, where all five bridges over the Ticino river were destroyed. After 9 September the medium bombers switched to attacking railway lines leading into Bologna and together with the fighter-bombers attacked targets immediately to the front of the 5th Army’s advance. In the period 9/20 September, when the weather broke, an average of 240 fighter sorties a day were flown, while on 9 and 11 September the medium bombers flew 337 sorties to attack positions on the Futa and Il Giogo passes, followed by strong attacks on their northern exits on 12/14 September.

After 16 September most of the medium bomber effort was switched to the 8th Army’s front. Here the Desert Air Force were making a tremendous sustained effort in support of the drive to Rimini, this effort peaking on 13 September when 900 sorties were flown and more than 500 tons of bombs were dropped. In the six days from 13 to 18 September, which included two days of bad weather, the Desert Air Force flew more than 4,000 sorties.

The medium bombers were now attacking the German positions on the Marecchia river, but on 20 September the weather broke completely, bringing air operations to a virtual standstill for five out of the final 10 days of the month. After the fall of Rimini the Desert Air Force had stretched out beyond the immediate front in an effort to prevent the Germans from regrouping and to attack the bridges over the Savio river and also the German communications in the triangle bounded by Ferrara, Bologna and Ravenna, while medium bombers attacked the marshalling yards between Bologna and Cesena.

As the weather became steadily worse in the first part of October, the scale of air operations fell sharply. The 'Gotisch-Linie' fighting had cost the Germans 8,000 men just as prisoners, and on 15 September the LXXVI Panzerkorps reported that, since the start of the battle, it had suffered 14,500 casualties. By 25 September more than one-third of Kesselring’s 92 infantry battalions were down to less than 200 men each and only 10 battalions had more than 400 men.

In just over three weeks of fighting up to 21 September, the 8th Army suffered more than 4,000 casualties and lost some 210 tanks, with even more bogged down or beyond any possibility of local repair. The Allied tank strength at the opening of the battle, excluding the relatively small number of tanks with the 5th Army, and any held at the base ports, had been 3,116. Three months later, in spite of the delivery of 363 'up-gunned' Sherman tanks, the figures stood at 3,014, showing an overall loss of 465 tanks, almost entirely in the 8th Army’s sector.

Between 10 September and 26 October, the US II Corps of the 5th Army sustained more than 15,700 casualties in the four divisions involved in the drive on Bologna, one-third of these casualties being in the US 88th Division. The cumulative effort of Allied losses since the fall of Rome may be judged from the fact that between 5 June and 15 August the 5th Army’s casualties in killed, wounded and missing had amounted to 17,959, and in the three months from July to September the 8th Army had suffered 19,975 battle casualties, of which 8,000 came in the period from 25 August to 9 September. The greatest losses were among the infantry units, and in the 'Gotisch-Linie' battles British infantry regiments lost more than 7,000 men.

Alexander had to take drastic measures: the 1st Armoured Division was disbanded, one of the 56th Division’s brigades was reduced to a cadre, and all British infantry battalions were reorganised with three rather than four rifle companies. Apart from the acute problem of the lack of reinforcements, Alexander was also faced with extreme difficulty in replacing heavy weapons, tanks and vehicles. As mentioned above, Wilson had twice applied to the Combined Chiefs-of-Staff for reinforcements with which to undertake the offensive into northern Italy. In addition to asking for fresh US divisions and modern equipment for the Italian units which had come over to the Allied side, Wilson also asked for more Indian troops from the Middle East and reinforcements for the Polish II Corps.

No equipment was released for the Italian units and in the middle of August Wilson was told that the 78th Division could be expected from Egypt during September and that an Indian infantry brigade together with a Greek brigade would arrive during August, but that the maintenance of the Indian brigade in protracted operations would be limited by lack of suitable replacements. A British infantry brigade was being formed from units already in the Mediterranean, but would not be ready for some time. The Combined Chiefs-of-Staff went on to say that the release of US divisions depended on developments in France but that the 92nd Division and a Brazilian division would be sent to Italy.

So far as reinforcements for the Polish II Corps was concerned, early in September some 11,000 Polish soldiers were screened out of the prisoners taken in Normandy and within a relatively short time a first contingent of 4,000 men was sent to the Polish II Corps.