The 1st Panzer Division was en elite armored division of the Wehrmacht that was active from 15 October 1935 to 8 May 1945. The division was headquartered in Weimar, and it initially consisted of two panzer regiments, a motorized infantry brigade, a reconnaissance battalion, a divisional artillery regiment, and supporting ancillary formations. In 1938, the division participated in the Anschluss with Austria, followed by the Annexation of the Sudetenland. In September 1939, the division took part in the Invasion of Poland, and it also participated in the 1940 invasions of the Netherlands, Belgium, and France. During the Battle of France, the division lost just under 500 killed in action, relatively low losses. From 22 June 1941, the division took part in Operation Barbarossa, and by mid-August, it had just 44 tanks left from the 155 tanks that it had started out with. The division advanced on Leningrad until mid-October, when it was sent to take part in the Battle of Moscow. The division took part in the defense of the Rzhev Salient in early 1942, and it was resupplied with new tanks during the spring. During the winter of 1942-1943, the division suffered heavy losses during the defense against several Soviet attacks, and it was transferred back to France in January 1943 for refitting. In June 1943, the division was sent to Greece, and it participated in the disarming of Italian forces in Greece after the Italian armistice in September 1943. In October 1943, the division was brought back to full strength when it received a substantial number of Panther and Tiger I tanks, and it was sent back to the Eastern Front. The division served alternatively in the 1st Panzer Army and the 4th Panzer Army as an emergency force. By March 1944, the division had been reduced to 25% of its original strength as the result of several battles in Ukraine, and it withdrew into Hungary. The division took part in defensive operations around Lake Balaton and the unsuccessful attempt to break through the Siege of Budapest, once more suffering heavy losses. In May 1945, the division engaged in the defense of Styria in Austria, and it surrendered to the US Army in southern Bavaria on 8 May 1945.