the French Second Army. Guderian saw things differently, and pointed out that a thrust along the lines of Kleist's plan would put the flank of the advance within range of the fortress artillery at Charleville-Mézières, some northwest of Sedan. The shift of operations further north would also disperse concentration (or Schwerpunkt) and disrupt the intense planning of the German tactical units, who had been in training for the Sedan attack and an advance north-west, for months. He also felt that a regrouping period in front of Sedan would delay the assault for 24 hours and allow the French to bring up reinforcements. Kleist agreed that such a delay was unacceptable, so he agreed to Guderian's plan. Panzer Group Kleist overwhelmed the French defenses at Sedan, advanced west and reached the sea, forming a huge pocket containing several Belgian, British, and French armies. Invasion of Yugoslavia Kleist was promoted to Generaloberst on 19 July 1940 and received the Knight's Cross of the Iron Cross. In April 1941 Panzer Group Kleist was renamed to 1st Panzer Group and spearheaded the invasion of Yugoslavia. Deployed against central Yugoslavia (Serbia), units of the 1st Panzer Group were the first to enter Belgrade. Invasion of the Soviet Union In June 1941 with the launching of Operation Barbarossa, Kleist led the 1st Panzer Group as part of Army Group Southtasked with the capture of Moldavia and Ukraineand saw success in the initial phase of the invasion, advancing deep into Ukraine. The 1st Panzer Group broke through the Stalin Line, then defeated the five mechanized corps of the Soviet 5th Army and 6th Army in the Battle of Brody (23 to 30 June 1941). In July 1941 during the Battle of Uman, the 1st Panzer Group broke through the Soviet Southern Front's lines, leading to the encirclement and annihilation of the Soviet 6th and 12th armies to the southeast of Uman city (in present-day Cherkasy Oblast). During the First Battle of Kiev of August–September 1941, 1st Panzer Group's northward turn from central Ukraine in conjunction with 2nd Panzer Group's southward advance from Smolensk led to the encirclement and destruction of the entire Soviet Southwestern Front east of Kiev, inflicting over 600,000 losses on the Red Army. However, the campaign had been costly, by then the German forces had just half the tanks they had had three months earlier. After operations at Kiev concluded, Kleist's 1st Panzer Army