The First Battle of Kiev was the German name for the operation that resulted in a huge encirclement of Soviet troops in the vicinity of Kiev (present-day Kyiv) during World War II. This encirclement is considered the largest encirclement in the history of warfare (by number of troops). The operation ran from 7 July to 26 September 1941, as part of Operation Barbarossa, the Axis invasion of the Soviet Union. Much of the Southwestern Front of the Red Army (commanded by Mikhail Kirponos) was encircled, but small groups of Red Army troops managed to escape the pocket days after the German panzers met east of the city, including the headquarters of Marshal Semyon Budyonny, Marshal Semyon Timoshenko and Commissar Nikita Khrushchev. Kirponos was trapped behind German lines and was killed while trying to break out. The battle was an unprecedented defeat for the Red Army, exceeding even the Battle of Białystok–Minsk of June–July 1941. The encirclement trapped 452,700 soldiers, 2,642 guns and mortars, and 64 tanks, of which scarcely 15,000 had escaped from the encirclement by 2 October. The Southwestern Front suffered 700,544 casualties, including 616,304 killed, captured, or missing during the battle. The 5th, 37th, 26th, 21st, and 38th armies, consisting of 43 divisions, were almost annihilated and the 40th Army suffered many losses. Like the Western Front before it, the Southwestern Front had to be recreated almost from scratch. Prelude July After the rapid progress of Army Group Centre through the central sector of the Eastern front, a huge salient developed around its junction with Army Group South by late July 1941. On 7–8 July 1941, the German forces managed to break through the fortified Stalin Line, in the southeast portion of Zhytomyr Oblast, which ran along the 1939 Soviet border. By 11 July 1941, the Axis ground forces reached the Dnieper tributary Irpin River ( to the west from Kiev). The initial attempt to enter the city right away was thwarted by troops of the Kiev ukrep-raion (KUR, Kiev fortified district) and counter offensive of 5th and 6th armies. Following that the advance on Kiev was halted and main effort shifted towards the Korosten ukrep-raion where the Soviet 5th Army was concentrated. At the same time the 1st Panzer Army was forced to transition to defense due to a counteroffensive of the Soviet 26th Army. A substantial Soviet force, nearly the entire Southwestern Front, positioned in and