Exploiting the capture of the Ludendorff Bridge at Remagen on 7 March 1945, the U.S. 12th Army Group under General Omar Bradley advanced rapidly into German territory south of Generalfeldmarschall (Field Marshal) Walter Model's Army Group B. In the north, the Allied 21st Army Group (Field Marshal Bernard Montgomery) crossed the Rhine in Operation Plunder on 23 March. The lead elements of the two Allied army groups linked up on 1 April 1945 east of the Ruhr to create a massive encirclement of 317,000 German troops to their west.