Seventh Army was struck by Operation Nordwind. Between 5 and 25 January 1945, there were four more major German attacks against the 6th Army Group by Heinrich Himmler's Army Group Oberrhein. Seventh Army suffered some 14,000 casualties, but the Germans did not break through, and Strasbourg was held. In Devers' estimation Brooks, the commander of VI Corps, "fought one of the great defensive battles of all times with very little". Devers now turned his attention to the Colmar Pocket. He had expected the Germans to withdraw and thought that the French First Army could reduce the pocket. He later admitted that he had underestimated the German determination to hold it and had overestimated de Lattre’s ability to keep moving against renewed and strengthened German resistance. Eisenhower regarded the pocket as a "sore" and sent five additional American divisions to 6th Army Group. After the Ardennes Offensive and Operation Northwind, Devers regarded it as petty of Bradley to begrudge him the additional divisions. French and American troops finally eliminated the Colmar Pocket on 5 February 1945. Against Eisenhower's preference, Devers was promoted to general on 8 March 1945, ahead of Spaatz, Bradley, and Patton, remaining the second-highest ranking American officer in Europe, after Eisenhower. Seventh Army crossed the Rhine on 26 March and began advancing into Germany. On 5 May 1945, General Hermann Foertsch surrendered Army Group G unconditionally to Devers. Patch, Haislip, and other American generals were present, but there was no representative of the French First Army. That caused a final diplomatic tussle with the French over the status of the German Twenty-Fourth Army, which de Lattre insisted should surrender to him. Devers refused to hand Schmidt over to de Lattre. Two days later, Eisenhower accepted a general surrender of the German armed forces at his headquarters at Reims. Army Ground Forces Following the surrender of Germany on 8 May 1945, Seventh Army was transferred to 12th Army Group, and the French First Army reverted to French control, which left 6th Army Group with little to do, although Devers acted as commander of 12th Army Group in Bradley's absence. In June 1945, Devers was appointed Chief of Army Ground Forces, in succession to General Joseph Stilwell, who had left to command the Tenth United States Army on Okinawa. Army Ground Forces still controlled schools and training centers in the United States, but their focus was demobilization and the co-ordination