'Avalanche' was the Allied first strategic landing on the Italian mainland in the Gulf of Salerno just to the south of Naples on the western coast (9/17 September 1943).

The operation was undertaken by Lieutenant General Mark W. Clark’s US 5^th Army, totalling the equivalent of nine divisions including Major General Matthew B. Ridgway’s US 82^nd Airborne Division.

The operation was planned as 'Top Hat', and its primary objectives were firstly the seizure of Naples, some 30 miles (48 km) to the north-west, as a working port for the effective supply of the increasing numbers of Allied troops scheduled to arrive on the Italian mainland, and secondly a rapid advance across the mainland from the west coast to the Adriatic Sea in an effort to trap the Axis troops in the south of the country.

After the defeat of the Axis powers in North Africa, where 'Vulcan' had forced the surrender of the last German and Italian forces in Tunisia on 13 May, there was disagreement between the Allies about their next move. Prime Minister Winston Churchill in particular wanted an invasion of Italy, which in November 1942 he called 'the soft underbelly of the axis', where popular support for the war was declining. Churchill believed an invasion would result in Italy’s surrender, and thus destroy the Axis strength in the Mediterranean theatre. This, Churchill believed, would fully open the Mediterranean to Allied shipping, and thereby significantly reduce the tonnage of scarce shipping capacity needed to supply the Allied forces in the Middle East and Far East at a time when there was crisis in the allocation of Allied shipping capacity, and also allow an increase in the delivery British and US matériel to the USSR. Churchill further believed that an Allied commitment in Italy would pin German forces that would otherwise be redeployed to the Eastern Front.

Premier Iosif Stalin had been pressing the Western Allies to open a 'second front' in Europe to weaken the German effort on the Eastern Front.

On the other hand, General George C. Marshall, the US Army chief-of-staff, and much of the US staff wanted to avoid operations that might delay the planned primary invasion of Europe on the shortest axis to Berlin, which had been discussed and planned as early as 1942 and finally materialised as 'Overlord'.

As it became clear that no primary invasion could be undertaken in 1943, it was agreed to invade Sicily in 'Husky' (i), but without any commitment to any successor operations in the Mediterranean theatre. However, Roosevelt and Churchill each accepted the need for the Western Allies to continue their engagement with the Axis powers in the period after the conclusion of a successful 'Husky' (i) and before the start of 'Overlord' in North-West Europe. The discussion continued through the 'Trident' third Washington conference in May, but it was not until a time late in July, after the course of the Sicily campaign had become clear and Benito Mussolini had fallen, that the Joint Chiefs of Staff instructed General Dwight D. Eisenhower, the Allied commander-in-chief in the Mediterranean theatre, to launch an invasion of the Italian mainland at the earliest possible date.

The Joint Allied Forces Headquarters was operationally responsible for all the Allied land forces in the Mediterranean theatre, and it was this body which planned and controlled the invasions of Sicily and then of the Italian mainland. The 'Husky' (i) invasion and conquest of Sicily was highly successful even though many of Axis troops managed to cross the Strait of Messina and reach the mainland. More importantly, on 24/25 July a coup deposed Mussolini as head of the Italian government, which then approached the Allies to make peace.

It was believed a quick invasion of Italy might hasten an Italian surrender and produce quick military victories over the German troops that could be trapped fighting in a hostile country. Before 'Husky' (i), Allied plans envisaged a crossing of the Strait of Messina, a limited invasion in the 'instep' area of the mainland in the area of Taranto, and an an advance north-east along the 'toe' of Italy from the area of Reggio di Calabria on the eastern side of the Strait of Messina in the face of German and Italian resistance.

The overthrow of Mussolini and his Fascist party made a more ambitious plan feasible, and the Allies decided to supplement the crossing of the British 8^th Army with a US-led seizure of the port of Naples. The Allies had a choice of two landing areas: one on the coast of the Volturno river basin just to the north of Naples, and the other at Salerno on the gulf just to the south of Naples. Both lay at the range limit of Allied fighters based in Sicily, but Salerno was chosen because it was slightly closer to these air bases, generally possessed milder surf conditions, allowed transport ships to anchor closer to the beaches, had narrower beaches for the rapid construction of exit roads, and possessed an excellent road network close behind the beaches.

The first step in the Allied progress onto the Italian mainland was 'Baytown', in which elements of Lieutenant General C. W. Allfrey’s V Corps of General Sir Bernard Montgomery’s 8^th Army would be delivered from Messina, on the north-eastern corner of Sicily, across the Strait of Messina directly by landing craft to come ashore near the tip of Calabria on 3 September 1943: Major General C. G. Bucknall’s 5^th Division would land on the north side of the 'toe' while Major General G. G. Simonds’s Canadian 1^st Division would land at Cape Spartivento on the south side. Montgomery was strongly opposed to 'Baytown' which, he predicted, would be a waste of effort since it assumed the Germans would give battle in Calabria; if they failed to do so, the diversion would not work, and the operation’s only effect would be to place the 8^th Army 300 miles (485 km) to the south of the main landing at Salerno.

Events proved Montgomery to be entirely correct: after 'Baytown' the 8^th Army had to march north to the Salerno area against no opposition other than engineer obstacles.

Plans for the use of airborne forces in support of the Salerno landing took several forms, all of which were cancelled. The initial plan to land gliderborne troops in the mountain passes of the Sorrento peninsula to the north of Salerno was abandoned 12 August. Six days later this initial thought was replaced by 'Giant I', in which two regiments of Ridgway’s 82^nd Airborne Division would descend on, seize and hold the crossings over the Volturno river to prevent the arrival of fresh Axis forces from the north. This plan was at first expanded to include the whole division, including an amphibious landing by the glider regiment, then deemed logistically unsupportable and reduced to a two-battalion drop at Capua to block Highway 6. The 3 September knowledge of the Italian armistice, to become effective on 8 September and be announced on the following day, led to the replacement of 'Giant I' by 'Giant II'. This was to be a drop by the 504^th Parachute Infantry on Stazione di Furbara and Cerveteri airfields, 25 miles (40 km) to the north-west of Rome, to aid Italian forces in saving Rome from the Germans, a condition of the Italian armistice.

Because the distance from the Allied beach-heads precluded any substantial Allied support of the airborne troops, Brigadier General Maxwell D. Taylor was infiltrated into Rome to assess the willingness of Italian troops to co-operate with the Americans. Taylor’s judgement was the operation would be a trap and he advised cancellation, which occurred late on the afternoon of 8 September as troop carriers were preparing to take off.

The main landings were 'Avalanche' scheduled for 9 September, when the main force would land around Salerno. This force was Lieutenant General Mark W. Clark’s US 5^th Army, comprising Major General Ernest J. Dawley’s four-division US VI Corps and Lieutenant General Sir Richard McCreery’s three-division British X Corps, with the 82^nd Airborne Division in reserve, a total of eight divisions and two brigade-sized units.

The operation’s primary objectives were to seize the port of Naples and thus ensure a means of resupply, and to drive across the 'leg' of Italy to the east coast, trapping the Axis troops farther south.

In the original planning, the great attraction of capturing the important port of Taranto in the 'heel' of Italy had been evident and an assault had been considered but rejected because of the very strong defences there. However, with the signing of the armistice with the Italians on 3 September the picture changed. It was decided that Major General G. F. Hopkinson’s British 1^st Airborne Division would be delivered to Taranto in British warships, seize the port and several nearby airfields, so facilitating the subsequent delivery of Allfrey’s V Corps and a number of fighter squadrons. On 4 September the airborne division, which was undergoing training exercises in two locations some 400 miles (640 km) apart, was ordered to embark on 8 September. With such short notice to create plans, 'Slapstick' was soon nicknamed 'Bedlam'.

Supported by a the 'Boardman' deception plan suggesting the imminence of an Allied invasion somewhere in the Balkans, 'Avalanche' was daring but possessed considerable dangers. The 5^th Army was to land on a front 35 miles (56 km) wide only three assault divisions (two British and one US in the X and VI Corps respectively), and the two corps were widely separated laterally by 12 miles (19 km) and also by the Sele river. Clark initially provided nothing to cover the river, which offered the Germans an easy route down which to launch a counterattack, and only belatedly landed two battalions to protect it. Moreover, the terrain favoured the defence.

The planning of 'Avalanche' was completed in just 45 days rather than the several months that might have been expected. A US Army Ranger force under Colonel William O. Darby, comprising three US Ranger battalions and two British Commando units, was tasked with holding the mountain passes leading to Naples, but no plan existed for linking the Ranger force with the X Corps' follow-up units. Finally, although tactical surprise was unlikely, Clark ordered no preparatory naval bombardment or naval gunfire support even though experience in the Pacific theatre had clearly demonstrated by this time that such support was essential. This omission resulted, at least in part, from the belief of Major General Fred L. Walker, commanding the US 36^th Division that was to land in the southern half of the beach-head, that General Traugott Herr’s defending LXXVI Panzerkorps was scattered too widely to be effective.

On the German side, Generalfeldmarschall Albert Kesselring, the Oberbefehlshaber 'Süd', did not have the forces with which to push the Salerno landing back into the sea, and was refused reinforcement in the form of the two Panzer divisions currently located in northern Italy. On 14 July the Germans had activated Generalfeldmarschall Erwin Rommel’s Heeresgruppe 'B' to control the German forces in Italy as far to the south as Pisa, with Kesselring commanding those in southern Italy. On 22 August the Germans also established a new formation, Generaloberst Heinrich-Gottfried von Vietinghoff-Scheel’s 10^th Army, to exercise direct control of Kesselring’s field formations.

The 10^th Army comprised two corps with six divisions positioned to cover possible landing sites. The XIV Panzerkorps, under the temporary command of Generalleutnant Hermann Balck and just in the process of taking over positions that had been held by the Italians, comprised Generalleutnant Paul Conrath’s Panzerdivision 'Hermann Göring', Generalmajor Eberhard Rodt’s 15^th Panzergrenadierdivision and Generalmajor Rudolf Sieckenius’s 16^th Panzerdivision). Herr’s LXXVI Panzerkorps comprised Generalmajor Smilo Graf von Lüttwitz’s 26^th Panzerdivision, Generalmajor Walter Fries’s 29^th Panzergrenadierdivision, and Generalleutnant Richard Heidrich’s 1^st Fallschirmjägerdivision. von Vietinghoff-Scheel astutely positioned the 16^th Panzerdivision in the hills above the Salerno plain.

As the launch date for 'Avalanche' approached, the Allies completed their plans for the 'Baytown' and 'Slapstick' subsidiary landings that were to be made farther to the south six days before and on the same day as 'Avalanche' respectively.

The Salerno landings began a little more than three hours after the announcement of the armistice between the Allies and Italy. The landings were made by McCreery’s X Corps on the left and Dawley’s VI Corps on the right. The former put ashore Major General J. L. I. Hawkesworth’s 46^th Division and Major General D. A. H. Graham’s 56^th Division (supported on their left flank by US Rangers and British commandos coming ashore at Maiori and Vietri) between Salerno in the north and the mouth of the Sele river in the south, and the latter Walker’s 36^th Division, with Major General Troy H. Middleton’s 45^th Division as the corps' floating reserve. The three assault divisions and their various supporting units were delivered onto a single large beach-head between Maiori and a point north of the mouth of the Sele river (two British divisions) and the mouth of the Sele river and Agropoli in the south (one US division).

In overall command of the amphibious operation was Admiral Sir Andrew Cunningham, and the primary force for the delivery and support of the 5^th Army was Task Force 80 (otherwise the Western Naval Task Force) commanded by Vice Admiral H. Kent Hewitt on the headquarters ship Ancon. Attached were the British anti-aircraft ships Ulster Queen and Palomares, and the beacon submarine was the British Shakespeare. TF81 (otherwise the Southern Attack Force) was commanded by Rear Admiral John L. Hall from the headquarters ship Samuel Chase, and comprised 18 transports, three tank landing ships (Boxer, Bruiser and Thruster), 27 tank landing ships, 32 infantry landing craft, six landing craft tank, four support landing craft, eight patrol craft, four submarine chasers , nine minesweepers, 12 yard minesweepers and 32 smaller vessels. These were to transport and land the VI Corps with the 36^th Division and 45^th Division off Paestum. Rear Admiral Lyal A. Davidson’s support group and escort comprised the US light cruisers Brooklyn, Philadelphia and Savannah, British monitor Abercrombie, Dutch gunboat Flores, and US destroyers Wainwright, Trippe, Rhind, Rowan, Plunkett, Niblack, Benson, Cleaves, Mayo, Knight, Dallas, Bernadou, Cole, Woolsey, Ludlow, Bristol and Edison.

Rear Admiral Richard L. Conolly’s TF85 controlled Commodore G. N. Oliver’s Northern Attack Force with the headquarters ships Hilary and Biscayne, eight transports, four infantry landing ships, 90 tank landing ships, 96 infantry landing craft, 84 tank landing craft, 23 submarine chasers and motor launches, seven minesweepers and four tugs. These were to transport and land the X Corps with the 46^th Division, 56^th Division, 7^th Armoured Division, US 3^rd Ranger Battalion Landing Team and two Royal Marine commandos.

Rear Admiral C. H. J. Harcourt’s support group and escort comprised the British light cruisers Mauritius, Orion and Uganda, anti-aircraft cruiser Delhi, monitor Roberts, destroyers Laforey, Lookout, Loyal, Nubian and Tartar, and escort destroyers Mendip, Dulverton, Tetcott, Belvoir, Brocklesby, Quantock, Blackmore, Brecon, Beaufort, Exmoor, Ledbury, Blankney and Greek Pindos (21^st Destroyer Flotilla).

Air support over the battlefield, as Salerno lay at the extreme range of tactical warplanes operating from Sicilian airfields, was entrusted to Rear Admiral Sir Philip Vian’s TF88 (otherwise Force 'V' and the Support Carrier Force) comprising the light carrier Unicorn, escort carriers Battler, Attacker, Hunter and Stalker, anti-aircraft cruisers Euryalus, Scylla and Charybdis, and escort destroyers Cleveland, Holcombe, Atherstone, Liddesdale, Farndale, Calpe, Haydon and Polish Krakowiak and Slazak.

Powerful overall cover was provided by Vice Admiral Sir Algernon Willis’s Force 'H' comprising the battleships Nelson and Rodney (Rear Admiral J. W. Rivett-Carcac) and Warspite and Valiant (Rear Admiral A. W. La T. Bisset), the fleet carriers Illustrious (Rear Admiral C. Moody) and Formidable (Rear Admiral A. G. Talbot), and the destroyers Quilliam, Queenborough, Quail and Petard (4^th Destroyer Flotilla), Troubridge, Tynan, Tumult, Offa and Polish Piorun (24^th Destroyer Flotilla) and Faulknor, Intrepid, Eclipse, Inglefield, Fury, Ilex, Echo, Raider and Greek Vasilissa Olga (8^th Destroyer Flotilla) as well as the large Free French destroyers Fantasque and Terrible.

In an attack by German torpedo-bombers during the night of 8/9 September, the battleship Warspite and carrier Formidable were only narrowly missed.

The landing succeeded on 9 September against strong and increasing German resistance, but at first the disembarked troops failed to reach their target positions in spite of strong gunfire support from the cruisers and destroyers. The monitor Abercrombie was damaged by a mine and the destroyer Laforey by five shell hits. Also damaged were LST-336, LST-357 and LST-385 by artillery fire, LST-375 by a bomb and LST-386 by a mine.

As the troops made slow progress on 10/11 September, during the night S-151, S-152 and S-158 of Kapitänleutnant Albert Müller’s 3^rd Schnellboots-Flottille attacked a US convoy and sank the destroyer Rowan. On 11 September heavy German air attacks began, and in these Dornier Do 217 twin-engined motherplanes of the II/Kampfgeschwader 100 and III/Kampfgeschwader 100 launched FX-1400 radio-controlled glide bombers and Henschel Hs 293 air-to-surface missiles. On 11 September Savannah was badly damaged by a direct hit and Philadelphia was only narrowly missed.

Committed soon after Eisenhower had broadcast the news of the Italian armistice with the Allied powers, the landings were carried out without the normal naval and/or aerial bombardment in an effort to achieve surprise, but the surprise was nevertheless far from total, as the naval commanders had predicted. Sieckenius, commanding the 16^th Panzerdivision, had established artillery and machine gun posts and scattered tanks through the landing zones, which made any Allied progress difficult, and deployed the bulk of his strength in four mixed-arms Kampfgruppen disposed about 6 miles (10 km) apart and between 3 and 6 miles (5 and 10 km) behind the beaches. Major Dörnemann’s Kampfgruppe 'Dörnemann' was just to the east of Salerno and therefore opposite 46^th Division’s landing, Oberst Stempel’s Kampfgruppe 'Stempel' was between Pontecagnano and Battipaglia and therefore faced the 56^th Division’s landing, Oberst Holtey’s Kampfgruppe 'Holtey' was in reserve at Persano on the Sele river which formed the corps boundary between X and VI Corps, and Oberst von Döring’s Kampfgruppe 'von Döring', which was responsible for the sector between Albanella and Rutino, was 4 miles (6.5 km) to the south-east of Ogliastro, somewhat to the south of the 36^th Division’s landing.

The X Corps (46^th and 56^th Divisions and a light infantry force of US Rangers and British Commandos of Brigadier R. E. Laycock’s 2^nd Special Service Brigade) experienced a mixed assortment of German reactions to its landings. The Rangers met no opposition, and with support from the guns of Ledbury, seized their mountain pass objectives. The men of No. 2 Commando and No. 41 (Royal Marine) Commando were also unopposed and secured the high ground on each side of the road to through the La Molina pass on the main route from Salerno to Naples. At first light units of No. 2 Commando moved toward Salerno and pushed back a small force of tanks and armoured cars of the 16^th Aufklärungsabteilung.

The two British infantry divisions, however, met determined resistance and had to fight their way ashore with the assistance of naval gunfire. The depth and intensity of German resistance forced British commanders to concentrate their forces, rather than driving to the south-east to link with the Americans to the south.

At Paestum, the two leading battalions of the 36^th Division’s 141^st and 142^nd Regimental Combat Teams were tackled by two companies of the Kampfgruppe 'von Döring'. The division had not been in combat before and, as an unfortunate byproduct of the Italian surrender, many of its men had come to believe that the landings would be little more than another training exercise. As a result, therefore, the 141^st RCT lost cohesion and failed to gain any depth during the day. This made it impossible to land supporting arms and stores, leaving the 141^st RCT without artillery and anti-tank guns. The 142^nd RCT did better, though, and with the support of the 143^rd RCT reserve unit that had landed by 08.00, was able to push forward.

By the end of 9 September the 5^th Army had failed to reach all its objectives, but had nonetheless had made a promising start: the X Corps' two assault divisions had pushed between 5 and 7 miles (8 and 11 km) inland, and the special forces had advanced to the north across the Sorrento peninsula to reach positions from which they could look down onto the Plain of Naples; and to the south the 36^th Division had established itself on the plain just to the south of the Sele river and the higher ground to a depth of 5 miles (8 km), although the 141^st RCT was still stuck near the beach. Both the British and US forces had made slow progress, and there was still a 10-mile (16-km) gap between them at the end of 9 September.

The two beach-heads had been combined into one by the end of the following day, however, and by that time occupied an area stretching 35 to 45 miles (56 to 72.5 km) along the coast to a depth of 6 to 7 miles (9.7 to 11.25 km) inland.

Commanding the XIV Panzerkorps, Balck was satisfied that the 16^th Panzerdivision's Kampfgruppen had performed as planned, and had ordered the Panzerdivision 'Hermann Göring' and 15^th Panzergrenadierdivision to move south against the Allied beach-head. To the east, meanwhile, the 29^th Panzergrenadierdivision of the LXXVI Panzerkorps had also been ordered to move to Salerno.

Neither side had gained the initiative, so for the next three days the Allies fought to expand their beach-head while the Germans defended stubbornly to mask the build-up of their reinforcements for a counter-offensive.

On 10 September Clark visited the beach-head and decided that it was unlikely that the X Corps would be able to push quickly east past Battipaglia to link with the VI Corps. Since the X Corps' planned primary axis of advance was to the north-west in the direction of Naples, Clark decided to move the VI Corps' left-hand boundary to the north of the Sele river and move the bulk of 45^th Division into the gap. In view of the approach of German reinforcements from the north, he also ordered a battalion-sized mixed-arms group to reinforce the Rangers on the following day.

During this same period, German reinforcements began to reach the battlefield as small units, short of transport and subjected to other delays, arrived piecemeal and were formed into Kampfgruppen for immediate committal to action. By 13 September, all the readily available reinforcements, including additional elements from the 3^rd Panzergrenadierdivision released by Kesselring from the area farther to the north near Rome, had arrived.

By contrast, the Allied build-up was constrained by the limited transport available for the operation, and also by the schedule of the build-up that had been fixed on the basis of how the planners had anticipated the development of the battle. Attempts to reinforce the beach-head were made unusually difficult by the possibility that these might have interrupted the all-important logistic effort to keep the two Allied corps supplied with ammunition, food and all the other necessities of war, but on 10 September and 13/14 September additional strength was to arrive in the form of the 45^th Division and 82^nd Airborne Division.

By 12 September it had become clear that 5^th Army had an acute shortage of infantry, and on the same day General the Hon. Sir Harold Alexander, Eisenhower’s deputy and commander of the Allied 15^th Army Group, reported to London that he was dissatisfied with the 'Avalanche' situation as the build-up was too slow and the landed forces were pinned down in a beach-head of tactically insufficient depth. Alexander added that he was pushing for an acceleration of the rate at which follow-on units and equipment was being delivered into the beach-head as a major German counterattack was inevitable.

By 12 September the X Corps had adopted a defensive posture because every battalion was committed and there were no reserves available to group as an attack force. In the south the 36^th Division made some progress, but toward 12.00 a counterattack by part of the 29^th Panzergrenadierdivision overran the 1/142^nd Infantry. On 13 September, the Germans launched their 'Orkan' counterattack. While the Kampfgruppen of the Panzerdivision 'Hermann Göring' attacked the beach-head’s northern flank, the main German effort was delivered onto the boundary between the X and VI Corps, which extended essentially from Battipaglia to the sea, with the greatest weight committed on the VI Corps' side of the line. During the morning of 13 September elements of 36^th Division attacked and captured Altavilla in the high ground some 9 miles (14 km) behind Paestum, but a counterattack forced its withdrawal as darkness fell.

During the afternoon, two German battle groups, the Kampfgruppe 'Kleine Limburg' and Kampfgruppe 'Krüger', had attacked Persano to the north-west and overrun the 1/157^th Infantry before crossing the Sele river to fall on the 2/143^rd Infantry and virtually destroy it. The Kampfgruppen continued their attacks to the south and south-west until reaching the confluence of the Sele river and the Calore river, the latter a large tributary of the Sele, where they were finally halted by a combination of artillery firing over open sights, naval gunfire and a makeshift infantry position manned by artillerymen, drivers, cooks and clerks and anyone else that Walker, commander of 36^th Division, could muster.

The VI Corps had by this time lost the best part of three battalions, so both its divisions' forward units were pulled back to reduce the length of the defensive line: the 45^th Division consolidated at the Sele and Calore position, and the 36^th Division was on the high ground on the seaward side of the La Caso stream, which flows into the Calore. The new perimeter was held with the assistance of the 82^nd Airborne Division. After the cancellation of 'Giant II', two of the division’s battalions, totalling 1,300 men of the 504^th Parachute Infantry, had been assigned to execute the final version of ' Giant I' at Capua on the evening of 13 September, but instead jumped into the beach-head and immediately moved into the line on the right of the VI Corps. On the following night, with the immediate crisis past, 2,100 men of the 505^th Parachute Infantry also dropped into the beach-head and reinforced the 504^th Parachute Infantry.

The fact that the crisis was effectively over was attested when, during the afternoon of 14 September, the 180^th Infantry (final regiment of the 45^th Division) landed, and Clark was able to place it in reserve rather than in the line. The 325^th Glider Infantry, reinforced by the 3/504^th Parachute Infantry, landed by sea on 15 September. A night drop of 600 men of the 2/509^th Parachute Infantry to disrupt German movements behind the lines in the vicinity of Avellino was widely dispersed and failed, and the battalion suffered heavy losses.

With strong gunfire support from British warships and the 5^th Army’s artillery, the reinforced and reorganised infantry defeated all German attempts on 14 September to find a weak spot in the Allied lines and the German losses, especially in armour, were severe. Moreover, on 14 September and the following night Air Chief Marshal Sir Arthur Tedder, heading the Allies' Mediterranean Air Command, ordered all available aircraft (including heavy bombers) to support 5^th Army: more than 1,000 tons of bombs were dropped during the daylight hours of that day.

On 15 September the 16^th Panzerdivision and 29^th Panzergrenadierdivision went over to the defensive, and this marked the end of the German thrust toward Paestum. Farther to the north, the Kampfgruppe 'Schmalz' of the Panzerdivision 'Hermann Göring' achieved surprise in an attack on Brigadier M. A. James’s 128^th Brigade of the 46^th Division on the high ground east of Salerno, but the armoured column following the Kampfgruppe was intercepted and driven back, leaving the German infantry exposed.

The Allied bombing continued on 15 September, although at a slightly reduced level than on the preceding day, as did the naval gunfire bombardment by the monitor Roberts, cruisers Mauritius, Uganda, Orion, Aurora, Philadelphia and Boise, and destroyers Loyal, Lookout, Tartar, Nubian, Brecon, Quantock and Eggesford operated close off the threatened assault area. But in German air attacks with FX-1400 and Hs 293 radio-controlled bombs and missiles Uganda was seriously damaged by a direct hit and Philadelphia, Loyal and Nubian were slightly damaged by near-misses. The hospital ship Newfoundland was sunk.

On 14 September the cruiser Penelope arrived and was soon followed by Euryalus, Scylla and Charybdis. A supply transport was heavily hit by bombs and sank on the following day. The arrival of the British battleships Warspite and Valiant, each armed with eight 15-in (381-mm) guns, provided the Allied troops with a major boost in morale as well as available firepower. Valiant was not required to shoot, and Warspite's 29 rounds were in fact only a minor contribution to the 2,592 naval rounds fired in that day.

On 15 September Kesselring reported to Berlin that the Allied air and naval superiority had forced the LXXVI Panzerkorps onto the defensive and that a decisive success would depend on the current attack by the XIV Panzerkorps: if this failed, Kesselring added, the 10^th Army would have to disengage to avoid being savaged. On 16 September the Kampfgruppe 'Schmalz' renewed its efforts on the X Corps' front but enjoyed no better success. The Allied air and naval forces continued to batter German targets, although during an air raid in which radio-controlled bombs were dropped, Warspite was hit and disabled, and had to be taken in tow to Malta for repair.

Away to the south, meanwhile, on 9 September the 8^th Army’s formations had been strung out along the coastal roads in the 'toe' of Italy. The build-up across the Strait of Messina had proceeded only slowly, and Montgomery’s forces were therefore short of transport. On 9 September, Montgomery decided to halt his formations in order to reorganise before resuming his advance, but on 10 September Alexander signalled the 8^th Army’s commander that the greatest importance had to be placed on the 8^th Army’s maintenance of pressure on the Germans so that they could not pull back units to reinforce their formations round Salerno. This message was further reinforced on 12 September by a personal visit from Major General A. W. C. Richardson, Alexander’s chief-of-staff.

So while reorganising the main body of the 8^th Army Montgomery despatched light forces up the coast to reach Castrovillari and Belvedere on 12 September, still some 80 miles (130 km) to the south of the Salerno battlefield. On 14 September Montgomery was able to start a more general advance, and by 16 September the 5^th Division had reached Sapri, 25 miles (40 km) beyond Belvedere, where forward patrols made contact with patrols of the VI Corps' 36^th Division.

On this day von Vietinghoff-Scheel told Kesselring that the Allied air and naval superiority were decisive, and that he lacked the strength to offset this. The 10^th Army had succeeded in preventing troops being cut off, and continuing the battle would serve no purpose other than invite heavy losses. The 8^th Army’s approach was now also now posing a new threat. von Vietinghoff-Scheel therefore recommended a German disengagement at Salerno to a new defensive line before starting a withdrawal on 18/19 September. Kesselring’s agreement reached von Vietinghoff-Scheel early on 17 September, the day on which 'Avalanche' may be said to have ended.

The operation had cost the Allies 2,009 men killed, 7,050 wounded and 3,501 missing out of a total of 189,000 landed by 16 September, while the Germans had suffered 3,500 casualties out of 100,000 men. With the Salerno beach-head now secure, the 5^th Army began its attack to the north-west in the direction of Naples on 19 September. After suffering serious casualties near Altavilla Silentina, the 82^nd Airborne Division was transferred to the X Corps, joining the Rangers and Brigadier R. H. E. Arkwright’s 23^rd Armoured Brigade on the Sorrento peninsula to flank the German defences at Nocera Inferiore, Sant’Antonio Abate and Angri, which the 46^th Division attacked.

Passing through the 46^th Division, Major General G. W. E. J. Erskine’s 7^th Armoured Division was assigned the task of taking Naples, while Major General Lucian K. Truscott’s newly landed US 3^rd Division took Acerno and Avellino on 22 and 28 September respectively.

The 8^th Army had been making good progress from the south in the face of German engineer actions and linked with the 1^st Airborne Division on the Adriatic coast. The left of the 8^th Army linked with the right of the 5^th Army right on 16 September, and advanced to the north along the Adriatic coast to capture the large airfield complex near Foggia on 27 September. This was a major Allied objective as its possession would give the Allied air forces the ability to strike new targets in France, Germany and the Balkans.

On 27 September there was an Italian rising in Naples, where the population believed that the Allies were at the gates of the city, but this uprising was very severely handled by the Germans in four days of incoherent fighting up to 1 October, when A Squadron of the King’s Dragoon Guards entered the city.

On 29 September a potent storm struck the Salerno area, and in this event one tank landing craft was lost, 12 tank landing craft were damaged, and 58 smaller landing craft were broached onto the beaches.

The whole of the 5^th Army, now comprising three British and five US divisions, reached the line of the Volturno river on 6 October. This provided a natural defensive barrier, securing Naples, the Campanian plain and the vital airfields on it from German counterattack. Meanwhile, on the Adriatic side of Italy the 8^th Army had advanced to a line from Campobasso to Larino and Termoli on the Biferno river.

The 10^th Army had come close to defeating the 'Avalanche' beach-head at Salerno. The determined early resistance by 16^th Panzerdivision's Kampfgruppen, combined with the ability of the Germans to reinforce them by land more quickly than the Allies could deliver follow-up forces by sea or air, had almost managed to tip the balance of the battle for the beach-head. The 5^th Army planners had concentrated the main weight of their forces in the X Corps on its left wing, in accordance with the primary objective of advancing on Naples. This had left the right wing thinly manned to defend the X Corps' right flank and left a particular weakness at the corps boundary.

Ultimately the Germans, aware of the limited time available for them to deal with the 'Avalanche' beach-head because of the inevitable arrival of the 8^th Army, had to make hurried and unco-ordinated attempts to force a quick decision, and thus failed to break through the Allied lines and exploit their gains in the face of total Allied air superiority and artillery and naval gunfire support.

The Allies had been fortunate that at this time Adolf Hitler had sided with the view of Rommel, and decided that the defence of Italy to the south of Rome was not a strategic priority. As a result, Kesselring had been forbidden to call upon reserves from Heeresgruppe 'B'. The success of the 10^th Army in inflicting heavy casualties combined with Kesselring’s strategic arguments led Hitler to agree that the Allies should be kept away from German borders and prevented from gaining the oil resources of the Balkans.

On 6 November Hitler withdrew Rommel to oversee the build-up of defences in northern France and gave Kesselring command of the whole of Italy with a remit to keep Rome in German hands for as long as possible.By a time early in October, the whole of southern Italy was in Allied hands, and the Allied armies stood facing the Volturno river as the Germans pressed ahead with the completion of the 'Reinhard-Linie' and 'Barbara-Linie' between the Volturno and Garigliano rivers. These constituted the first of a series of prepared defensive lines running across Italy from which the Germans chose to fight delaying actions, giving ground slowly and buying time to complete their preparation of the 'Gustav-Linie', their strongest defence line south of Rome.

The next stage of the Italian campaign became for the Allied armies an attritional and bitter struggle against skilfully sited and well prepared defences held by determined foes in terrain and weather conditions which favoured defence and hampered the Allied advantages in mechanised equipment and air superiority. It took until mid-January 1944 for the Allies to fight their way across the Volturno and through the 'Barbara-Linie' and 'Reinhard-Linie' to close on the 'Gustav-Linie', thus setting the scene for the four Battles of Monte Cassino which took place between January and May 1944.