The First Battle of Kiev was the German name for the operation that resulted in a very large encirclement of Soviet troops in the vicinity of Kiev 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 August to 26 September 1941 as part of Operation Barbarossa, the Axis invasion of the Soviet Union. In Soviet military history, it is referred to as the Kiev Strategic Defensive Operation, with somewhat different dating of 7 July – 26 September 1941.

Much of the Southwestern Front of the Red Army 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 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 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 the 38th armies, consisting of 43 divisions, were almost annihilated and the 40th Army suffered many losses.

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