500 men killed in action. The 1st Panzer Division remained in France until September 1940, when it was moved to East Prussia. It supplied a substantial number of units to the new 16th and 18th Panzer Divisions. From 22 June 1941, it took part of Operation Barbarossa, crossing the former German-Lithuanian frontier as part of the Army Group North and the 4th Panzer Group. The division was involved in heavy fighting and, by mid-August, had only 44, of the 155 tanks it had started out with less than two month earlier, left in serviceable condition. It continued to advance towards Leningrad until early October when it was transferred to the Army Group Centre to take part in the advance on Moscow. The division advanced within on Moscow before being forced to retreat during the Soviet counterattack. The division was part of the defence of the Rzhev Salient during early 1942, initially being very short on tanks and fighting predominantly as infantry until being resupplied during Spring. The 1st Panzer Division was engaged in the defence of the supply lines of the 9th Army in the centre of the Eastern Front. It suffered heavy casualties during the defence against repeated Soviet attacks in the Winter of 1942–43 before eventually being transferred back to France in January 1943 for refitting. After months in northern France, the division was sent to occupied Greece in June 1943 because of the perceived threat of an Allied landing there. Instead, the landing took place in Sicily and the division participated in the disarming of Italian forces in Greece when the former defected from the Axis in September 1943. The 1st Panzer Division was brought up to full strength again in October when it received a substantial number of Panther tanks and returned to the Eastern Front again shortly thereafter. The 1st Panzer Division was engaged in the southern sector of the Eastern Front to serve alternately within the 1st and 4th Panzer Army as an emergency force. It was constantly thrown from crisis location to crisis location as the German front lines retreated, taking part in battles at Kiev, Zhitomir and Cherkassy. The latter battle saw the division attempting to break through to the cauldron but falling just short. By March 1944, the division had been reduced to just over 25 percent of its nominal strength. Retreating further westwards, the division was part of the Kamenets-Podolsky