'Plunder' was the Allied offensive by Field Marshal Sir Bernard Montgomery’s Allied 21^st Army Group across the Rhine river to the north of the Ruhr industrial region in western Germany (23 March/1 April 1945).

Other than 'Overlord', this was the largest single operation undertaken by the British in World War II, the 21^st Army Group being able to call on 1.284 million men of General H. D. G. Crerar’s Canadian 1^st Army (eight divisions), Lieutenant General Sir Miles Dempsey’s British 2^nd Army (11 divisions including three armoured and two airborne, plus four armoured brigades, one infantry brigade and one commando brigade) in the 'Turnscrew', 'Widgeon' and 'Torchlight' sub-operations, and Lieutenant General William H. Simpson’s US 9^th Army (11 divisions including three armoured) in the 'Flashlight' sub-operation.

Also associated with 'Plunder' was the 'Varsity' airborne operation by Major General Matthew B. Ridgway’s US XVIII Airborne Corps (British 6^th and US 17^th Airborne Divisions) of Lieutenant General Lewis H. Brereton’s Allied 1^st Airborne Army,

The army group also had at its disposal some 5,480 pieces of field, anti-tank and anti-aircraft artillery.

The German opposition was found by Generaloberst Johannes Blaskowitz’s Heeresgruppe 'H', which disposed of two armies in the form of the 25^th Army (controlled directly by Blaskowitz) and General Günther Blumentritt’s 1^st Fallschirmarmee. The Germans expected that Montgomery’s assault over the Rhine river would take place downstream of Emmerich, and it was here that the 25^th Army, the stronger of Blaskowitz’s two weak armies, was disposed. This left the 1^st Fallschirmarmee to cover the 45-mile (72.5-km) sector between Emmerich and Duisburg with a mere eight poor-quality divisions in three corps (two corps each with three divisions and one corps with two divisional formations). The strongest of these corps was Generalleutnant Eugen Meindl’s II Fallschirmkorps, located at Rees, but even this had a mere 12,000 men under command. The 1^st Fallschirmarmee's sole mobile reserve was General Heinrich Freiherr von Lüttwitz’s XLVII Panzerkorps with Generalmajor Siegfried von Waldenburg’s 116^th Panzerdivision and Oberst Wolfgang Maucke’s 15^th Panzergrenadierdivision, which had just 35 tanks between them.

Both the Oberkommando der Wehrmacht and Generalfeldmarschall Albert Kesselring, now once again the Oberbefehlshaber 'West', expected that that Allies would preface the obviously forthcoming operation with an airborne assault, probably against the high ground covering Wesel, the primary strategic target in the sector, and so allocated to Heeresgruppe 'H' a complete Flak corps to supplement the army group’s already powerful artillery forces, which included one Volksartilleriekorps and one Volkswerferbrigade.

In fact Montgomery had decided to make his main effort upstream of Emmerich, in the sector where the 2^nd Army faced the 1^st Fallschirmarmee. Montgomery’s original plan had called for Lieutenant General G. G. Simonds’s Canadian II Corps of the Canadian 1^st Army and Major General John B. Anderson’s US XVI Corps of the US 9^th Army to be allocated to the 2^nd Army for 'Plunder', but vociferous US objections led to a modification whereby the 9^th Army undertook its parallel 'Flashpoint' operation just to the right of the 2^nd Army.

The Allied plan was thus for the 2^nd Army to cross the Rhine river, which is between 300 and 500 yards (275 and 460 m) wide in this area of flooded and deserted farm land rising to wooded hills, at Rees against the right wing of the II Fallschirmkorps (Generalleutnant Hermann Plocher’s 6^th Fallschirmjägerdivision and Generalmajor Walter Wadehn’s 8^th Fallschirmjägerdivision), at Xanten against the left wing of the II Fallschirmkorps (Generalleutnant Wolfgang Erdmann’s 7^th Fallschirmjägerdivision) and the right wing of General Erich Straube’s LXXXVI Corps (part of Oberst Heinz Fiebig’s 84^th Division), and at Wesel against the centre of the LXXXVI Corps (part of the 84^th Division), and for the XVI Corps to cross at Walsum against the left wing of the LXXXVI Corps (Generalmajor Bernhard Klosterkemper’s 180^th Division supported by Generalleutnant Walter Steinmüller’s Division 'Hamburg').

Montgomery planned to reallocate Wesel to the Americans once the bridge-head on the eastern bank of the Rhine river had been secured so that Simpson would have the use of two bridgeheads for the launch of his two-corps exploitation.

The whole operation was a monumental exercise in logistics, for the Allied planners had decided on a huge artillery preparation by some 4,000 pieces of artillery (the 2^nd Army had 60,000 tons of additional ammunition), and also realised that the establishment of bridges would also be a vast undertaking, requiring the services of 37,000 British and 22,000 US engineers. The 2^nd Army had 30,000 tons of engineer equipment as part of its allocation of 118,000 tons of additional stores, and the 9^th Army had 138,000 tons of additional stores.

Before the bridges could be thrown across the Rhine river, the Allied assault formations had first to cross this major barrier and establish bridgeheads on the eastern bank. This task was undertaken by large numbers of assault craft and amphibious vehicles, while the movement of heavier weapons and bridging equipment was entrusted to a special Royal Navy detachment under Vice Admiral Sir Harold Burrough and equipped with 45 LCM medium landing craft and a similar number of LVC(P) vehicle and personnel landing craft. These were shipped to Ostend from the UK in an landing ship dock and then travelled under their own power to Antwerp for collection and delivery to the Rhine by a fleet of army tank transporters.

Elaborate deception and camouflage schemes, including a massive smoke screen from 16 March, were adopted in an effort to conceal this mass of Allied preparations from the Germans, and it was also decided that while the artillery deluged the German forward positions on the Rhine river, the Allied air forces would operate slightly farther to the rear of the German forward positions in the period before the assault in order to seal off the battlefield. In this campaign RAF Bomber Command and the US 8^th and 9^th Army Air Forces, commanded respectively by Air Chief Marshal Sir Arthur Harris, Lieutenant General James H. Doolittle and Lieutenant General Hoyt S. Vandenberg, flew some 16,000 sorties between mid-February and 21 March, and dropped 49,500 tons of bombs on the German rear areas, effectively destroying all lines of communication.

Between 11 and 21 March this major bombing effort was supplemented by the tactical operations of Air Marshal Sir Arthur Coningham’s British 2^nd Tactical Air Force and Brigadier General Richard E. Nugent’s US XXIX Tactical Air Command, which between them flew 7,300 sorties.

Montgomery’s huge artillery bombardment started at 17.00 on 23 March, and continued with breaks until 09.45 on the following morning. During the night the first assault crossings were successfully implemented. In the north, Lieutenant General B. G. Horrocks’s British XXX Corps put across the river, just to the north of Rees, four battalions of Major General T. Rennie’s 51^st Division. Slightly farther to the south Lieutenant General Sir Neil Ritchie’s British XII Corps put across the river, in the area opposite Xanten, Major General C. M. Barber’s 15^th Division. Farther to the south still Brigadier the Lord Lovat’s 1^st Commando Brigade crossed to Wesel and engaged the 180^th Division in the wasteland which had been the city. And in the extreme south of the operation the XVI Corps sent over Major General Leland S. Hobbs’s 30^th Division and Major General Ira T. Wyche’s 79^th Division between Wesel and Walsum.

Shattered by artillery fire on top of the weeks-long aerial bombardment and total defeatism at this last stage of the war, the Germans offered only minimal resistance and the Allies thus secured extensive bridgeheads all along their front. But dawn saw a reversal of this trend, especially in the north, where the German airborne formations began to fight back with extreme tenacity. Blaskowitz thought that he had perceived the nature of the Allied offensive, and so ordered General Heinrich Freiherr von Lüttwitz’s XLVII Panzerkorps to move to the south from the 25^th Army's sector with Generalmajor Siegfried von Waldenburg’s 116^th Panzerdivision and Generalleutnant Eberhardt Rodt’s 15^th Panzergrenadierdivision.

The Germans had been deceived by their belief that the Allies would undertake an airborne operation at the same time as their river crossing, probably deep in the German rear to create an air-head which would be held until relief and/or exploitation forces arrived to complete the vertical envelopment of the 1^st Fallschirmarmee with conventional ground operations. But Montgomery opted instead for the 'Varsity' airborne drop shortly after the crossing and barely 5 miles (8 km) into the German rear at Hamminkeln to open the German centre. Under the command of Ridgway’s XVII Airborne Corps, Major General E. Bols’s British 6^th Airborne Division and Major General William E. Miley’s US 17^th Airborne Division landed with minimal casualties, took or silenced most of the German heavy artillery batteries, and then drove to the west through the Diersfordterwald to link with the XII Corps. The XVII Airborne Corps also took key points on the IJssel river, which runs parallel with the Rhine river between Wesel and Emmerich, and which could have been used by the Germans as an effective fall-back line.

Caught between two forces, the 84^th Division was virtually destroyed, and by the fall of night on 24 March the Allies had secured a bridgehead some 30 miles (48 km) wide and up to 5 miles (8 km) deep. It was now time for the consolidation and development phase so that Montgomery could commit his other four corps to the exploitation. By 26 March the development was well under way, with seven 40-ton bridges open to Allied traffic across the Rhine river, allowing Montgomery to move into the bridgehead two important armoured formations, namely Major General L. O. Lyne’s British 7^th Armoured Division of the XII Corps and Brigadier General John M. Devine’s US 8^th Armored Division of the XVI Corps. By 24.00 on 28 March these two formations had considerably expanded the size of the Allied bridgehead, the 7^th Armoured Division having pushed forward some 20 miles (32 km) as far as Borken, and the 8^th Armored Division about 25 miles (40 km) as far as Haltern, with other elements of the British 2^nd Army and Canadian 1^st Army driving into northern Germany and toward the southern part of the Netherlands, and the US 9^th Army pushing to the south into the northern part of the Ruhr industrial complex between Duisburg and Essen.

Still farther to the south, Lieutenant General Courtney H. Hodges’s US 1^st Army of Lieutenant General Omar N. Bradley’s US 12^th Army Group had broken out of its Remagen bridgehead and swept to both the east and north. Leading elements of the US 9^th Army and US 1^st Army (Devine’s 8^th Armored Division and Major General Maurice Rose’s 3^rd Armored Division) met at Lippstadt to the east of the Ruhr on 2 April, trapping what was left of Generalfeldmarschall Walter Model’s Heeresgruppe 'B' (Generaloberst Josef Harpe’s 5^th Panzerarmee and General Gustav-Adolf von Zangen’s 15^th Army) in the Ruhr pocket together with the LXIII Corps of the crushed 1^st Fallschirmarmee. This pocket contained 19 divisions of five corps, which Adolf Hitler designated the Festung 'Ruhr'.

The Battle of the Ruhr Pocket which followed was a encirclement battle which took place late in March and early in April, and marked the end of major organised resistance on Germany’s Western Front, as more than 300,000 men were taken prisoner.

The strategic situation was set in March 1945 by the Allied forces' crossings of the Rhine river. To the south of the Ruhr, the pursuit by Bradley’s US 12^th Army Group of the disintegrating German forces in front of it resulted in the capture of the Ludendorff Bridge across the Rhine river at Remagen by the US 1^st Army. Bradley and his subordinates quickly exploited the crossing made on 7 March 1945 to expand the bridgehead until the bridge collapsed 10 days later. To the north of the Ruhr, on 23 March Montgomery’s Allied 21^st Army Group launched 'Plunder' to cross the Rhine river at Rees and Wesel.

After crossing the Rhine river, both army groups exploited ever deeper into Germany. In the south, while Lieutenant General George S. Patton’s US 3^rd Army headed to the east, Hodges’s US 1^st Army headed to the north-east and formed the southern pincer of the Ruhr envelopment. In the north, Simpson’s US 9^th Army, which since the Battle of the Bulge had been assigned to Montgomery’s 21^st Army Group, headed to the south-east and formed the northern pincer even as the rest of 21^st Army Group advanced to the east and north-east.

Facing the Allied armies were the remnants of German army formations and units, a few Waffen-SS operational and training formations and units, and large numbers of Volkssturm (militia units of older men) and Hitlerjugend units (boys as young as 12).

The leading elements of the two pincers met on 1 April near Lippstadt, and by 4 April the encirclement of the Ruhr had been completed and the US 9^th Army reverted to the command of Bradley’s 12^th Army Group. Within the Ruhr pocket about 430,000 German soldiers of Model’s Heeresgruppe 'B', which comprised 21 divisions, together with millions of civilians were trapped in cities heavily damaged by numerous bombings.

While the bulk of the Western Allies' forces pushed on to the east and their junction with the Soviet forces on the Elbe river, the Ruhr pocket was left to be crushed by Lieutenant General Leonard T. Gerow’s specially formed US 15^th Army with 18 divisions of the US 1^st Army and US 9^th Army in five corps.

On 12 April the US 15^th Army divided the area as its US 1^st Army element advanced from the south, and the smaller, eastern part of the pocket surrendered on the following day. The western part, itself divided into two parts, continued a weak resistance until 18 April and 21 April. Rather than surrender and violate his personal oath to Adolf Hitler that he would fight to the death, Model committed suicide in a forest south of the city of Duisburg on 21 April, and on the same day Generaloberst Josef Harpe of the 5^th Panzerarmee surrendered the last part of the pocket, which yielded 325,000 prisoners including 29 generals.