The 1st Panzer Army () was a German tank army that was a large armoured formation of the Wehrmacht during World War II. When originally formed on 1 March 1940, the predecessor of the 1st Panzer Army was named Panzer Group Kleist (Panzergruppe Kleist) with Colonel General Ewald von Kleist in command. Service history Panzer Group Kleist was the first operational formation of several Panzer corps in the Wehrmacht. Created for the Battle of France on 1 March 1940; it was named after its commander Ewald von Kleist. Panzer Group Kleist played an important role in the Battle of Belgium. Panzer corps of the Group broke through the Ardennes and reached the sea, forming a huge pocket, containing several Belgian, British, and French armies. When the armistice was signed, the Group was deployed in occupied France, being renamed to Panzer Group 1 (Panzergruppe 1) in November. In April 1941, Panzer Group 1 took part in the invasion of Yugoslavia as part of Field Marshal Maximilian von Weichs's Second Army. 1941 In May 1941 Panzer Group 1 was attached to Field Marshal Gerd von Rundstedt's Army Group South at the beginning of Operation Barbarossa. At the start of Operation Barbarossa in June 1941, Panzer Group 1 included the III, XIV and XLVIII Army Corps (motorized) with five panzer divisions and four motorized divisions (two of them SS) equipped with 799 tanks. Panzer Group 1 served on the southern sector of the Eastern Front against the Red Army and was involved the Battle of Brody which involved as many as 3,000 Red Army tanks. The units of the Group closed the encirclement around the Soviet armies near Uman and near Kiev. After the fall of Kiev Panzer Group 1 was enlarged to become the 1st Panzer Army (on October 6, 1941) with Kleist still in command. The army captured Rostov, but was forced to retreat eight days later. 1942 In January 1942, Army Group Kleist, which consisted of the First Panzer Army along with the Seventeenth Army, was formed with its namesake, Kleist, in command. Army Group Kleist played a major role in repulsing the Red Army attack in the Second Battle of Kharkov in May 1942. Army Group Kleist was disbanded that month. The First Panzer Army, still under Kleist, which had been attached to Army Group South earlier, became part of Army Group A under Field Marshal Wilhelm List. Army