'Blackcock' (ii) was a British operation by Lieutenant General N. M. Ritchie’s XII Corps of Lieutenant General Sir Miles Dempsey’s 2^nd Army to clear the Roermond triangle (bounded by Roermond, Sittard and Heinsberg) and so destroy the German salient of General Gustav-Adolf von Zangen’s 15^th Army, within Generalfeldmarschall Walter Model’s Heeresgruppe 'B', between the Maas river and the Roer and Würm rivers (14/26 January 1945).

As 'Wacht am Rhein' continued in the Ardennes region, Field Marshal Sir Bernard Montgomery seized the opportunity for formations of his 21^st Army Group to take the single area remaining to the Germans in the area to the west of the Roer river. This was the Heinsberg salient, which was an essentially equilateral triangle with sides about 20 miles (32 km) long and with its apex at Roermond and its base along the Säffelen Beek running into the Maas river at Maeseyck. From Sittard, two main roads extended in the east and west respectively to Heinsberg and Roermond, which were both parts of the 'Siegfried-Linie' defences. The area was held by two German formations, namely Generalmajor Christian-Johannes Landau’s 176^th Division and Generalleutnant Wolfgang Lange’s 183^rd Volksgrenadierdivision, but neither of these was of the calibre of the divisions which had been committed to 'Wacht am Rhein'. Constituting part of General Günther Blumentritt’s (from 20 January Generalleutnant Fritz Bayerlein’s) XII SS Corps, the two divisions were nonetheless well supported by the skilfully sited heavy artillery of the 'Siegfried-Linie' defences.

The planning of 'Blackcock' (ii) demanded extreme staff work competence by the XII Corps, a high standard of leadership by the regimental officers of the infantry units involved, and a combination of great courage and endurance by the troops. There was little or no scope for air support, and armoured support was rendered impossible on many occasions by the bad going and the size and density of the German minefields.

Flanked to its north by Lieutenant General E. H. Barker’s VIII Corps of the 2^nd Army and to its south by Lieutenant General William H. Simpson’s US 9^th Army, the operation was entrusted primarily to Major General R. K. Ross’s 52^nd Division, which was to advance via Bocket toward the core of the German defences at Heinsberg. Major General L. O. Lyne’s 7^th Armoured Division and Major General G. I. Thomas’s 43^rd Division (under the temporary command of Brigadier B. A. Coad) were allotted secondary roles on the 52^nd Division’s left and right respectively: the former was to advance via Susteren toward Roermond, and the latter via Waldenrath toward Dremmen and Lindern. Right-flank protection for 'Blackcock' (ii) was provided in the Lindern area by Major General Frank A. Keating’s US 102^nd Division of the US 9^th Army.

Mindful of the need to conserve manpower for the advance into Germany and with a view to familiarising the infantry with the techniques of working with the Flail mineclearing, Petard obstacle-breaching, Crocodile flamethrowing and Kangaroo troop-carrying armoured vehicles of Major General Sir Percy Hobart’s 79^th Armoured Division, Montgomery provided formidable artillery support: the fire of eight field regiments, six medium regiments and some heavy and super-heavy guns could be called upon. A further novelty was the Canadian 1^st Rocket Battery’s rocket launcher system, which could fire a salvo of some 350 rockets, each equivalent to a 5.5-in (139.7-mm) shell: this was known to the troops as the 'Canadian Mattress' or 'Flying Bedstead'. Lastly, there was a troop of searchlights, whose beams reflected from the sky produced 'Monty’s Moonlight', giving enough light to enable troops assaulting in the dark to see their way. For the troops snow suits provided admirable camouflage; tanks and other vehicles were painted white.

Every phase of the operation was planned in great detail and previously rehearsed, and the men were rested and fed before entering action with every man understanding the part he had to play.

By the end of 1944 the front line in the Dutch province of Limburg had stabilised along several natural barriers. By far the most difficult barrier to cross was the Maas river marking the border between Belgium and the Netherlands. The next barrier was the Roer river running from the Eifel area of Germany through Heinsberg toward Roermond, where it joins the Maas river. To the south of Heinsberg the defences of the 'Siegfried-Linie' or 'Westwall' extended along the banks of the Roer river.

The southern part of Limburg had been liberated in September 1944 by Simpson’s US 9^th Army, but the area to the north of the line, extending between Sittard and Geilenkirchen, remained in German hands. Here the front had settled along the Säfeller Beek, a stream forming another seemingly immense obstacle. These obstacles formed a triangular area, generally known as the 'Roermond Triangle', which thrust westward into the Allied front. As a result of the German 'Wacht am Rhein' offensive in the Ardennes, the Allies had been compelled to withdraw resources to stop the German advance in the sector of Lieutenant General Courtney H. Hodges’s US 1^st Army. Therefore the XII Corps had been allocated responsibility for the front north of Sittard, with the Maas river front held by Barker’s VIII Corps. The XII Corps faced the XII SS Corps, which had Landau’s 176^th Division and Lange’s 183^rd Volksgrenadierdivision along the front between Geilenkirchen and Roermond. Just to the south of Roermond the 176^th Division was strengthened by Oberstleutnant Friedrich Hübner’s Fallschirmjägerregiment 'Hübner'.

The British clearance of the Roermond Triangle was planned on the basis of advances of three axes. The left-hand axis, entrusted to the 7^th Armoured Division, was directed at the capture of the bridge across the Roer river at Sint-Odiliënberg after the division had started by bridging the streams to the south of Susteren. The central axis, entrusted to the 52^nd Division, was directed at the capture of Heinsberg after this formation had kicked off with a breakthrough of the German line near Hongen to open the road between Sittard and Heinsberg for the forward movement of the relevant troops. The right-hand axis, entrusted to the 43^rd Division, was directed at the clearance of the area to the south-east of Dremmen via the break in the German line created by the 52^nd Division.

The decisive point of 'Blackcock' (ii) was the battle for the small Dutch village of Sint-Joost. After four days of fighting the Germans were fully conscious of the fact that the 7^th Armoured Division facing them was heavily reliant on the roads to manoeuvre its armour, for in the prevailing winter conditions the ground was too soft for effective tank movement. Sint-Joost lay on the 7^th Armoured Division’s route to the north in the direction of Montfort.

In cold and misty conditions, the British division’s armoured and infantry units began their first attack on 20 January against what was believed to be two companies of the 2/Fallschirmjägerregiment 'Hübner' in Sint-Joost. The attack failed, and so too did the following pair of attacks before a fourth attempt, on 21 January, finally succeeded in clearing the village. The British captured 60 German paratroopers and counted more than 100 German dead, but both the 9/Durham Light Infantry and 1/Rifle Brigade had also suffered: the former had taken 33 casualties including eight killed, and the latter 34 casualties including three killed. The German battalion had lost one complete company, with a second severely mauled. 'Crocodile' flame-throwers based on the Churchill infantry tank supported the Rifle Brigade’s first attack on the village, and many of Sint-Joost’s houses were destroyed by the efforts of these armoured vehicles.

Between the evening of 19 January and 23 January the Dutch village of Montfort, to the north-east of Sint-Joost, was shelled or bombed seven times, and was hit by more than 100 bombs, most of them in the centre of the village. Nearly all of the 250 houses were damaged, some to become nothing but ruins, and there were instances of whole families being killed. During these bombing raids the Germans took shelter in the cellars among the civilians, and in the wooded areas just outside the village. The bombing raids of 21/22 January were undertaken by the Hawker Typhoon single-engined fighter-bombers of the Canadian 143^rd Wing (Nos 428, 439 and 440 Squadrons) of Air Vice Marshal H. Broadhurst’s No. 83 Group of Air Marshal Sir Arthur Coningham’s British 2^nd Tactical Air Force. Operating from Eindhoven, the wing lost six aircraft during 'Blackcock' (ii), two of these crashing in Montfort.

When the village was finally liberated by the 7^th Armoured Division on 24 January, the British troops found the surviving villagers profoundly shocked, for the air attacks had cost the lives of 186 civilians, most of them buried under their destroyed homes.

'Blackcock' (ii) as a success for the Allies as all their objectives were attained. The German divisions were driven out of the Roer Triangle with exception of the area immediately south of Roermond. Here the Fallschirmjägerregiment's men remained in temporary control. The British formation which undertook the hardest task in the operation was the 52^nd Division, which suffered 752 casualties, including 101 killed; another 258 men were declared unfit because of sickness, mostly from the adverse weather conditions and the extreme cold. The 7^th Armoured Division had just slightly more than 400 casualties, but in matériel terms fared somewhat better with just 20 tanks knocked out by the Germans and another 23 rendered unserviceable by mechanical problems: of the knocked-out tanks 10 were damaged beyond repair, and the other 10 could be repaired. The number of German casualties is unknown, but can be estimated as about 2,100: the 7^th Armoured, 52^nd and 43^rd Divisions took 490, more than 1,200 and about 400 prisoners respectively.

Once 'Blackcock' (ii) had been brought to the desired conclusion on 26 January, the Allied plans for the capture of the Rhineland could be started. 'Veritable' by the Canadian 1^st Army was launched on 8 February and aimed at breaking through the German line in the Reichswald, some 37 miles (60 km) north of the Roer Triangle. 'Grenade' by the US 9^th Army was launched on 23 February as this formation crossed the Roer river to the south of Heinsberg. Within 12 hours the US 9^th Army had 16 battalions on the eastern bank, together with seven heavy bridges and a number of light assault bridges. A task force of Major General John B. Anderson’s US XVI Corps rushed toward Venlo to meet with the British in the north, and on 1 March Roermond was taken by a reconnaissance troop of Major General Paul W. Baade’s US 35^th Division without a single shot being fired.