The Battle of Moscow, was a military campaign that consisted of two periods of strategically significant fighting on a 600 km (370 miles) sector of the Eastern Front during World War II. It took place between October 1941 and January 1942. The Soviet defensive effort frustrated Hitler's attack on Moscow, the capital of the Union of Soviet Socialist Republics (USSR) and the Soviet Union's largest city. Moscow was one of the primary militaryand political objectives for Axis forces in their invasion of the Soviet Union.
The German strategic offensive, named Operation Typhoon (German: Unternehmen Taifun), called for two pincer offensives, one to the north of Moscow against the Kalinin Front by the 3rd and 4th Panzer Armies, simultaneously severing the Moscow–Leningrad railway, and another to the south of Moscow Oblast against the Western Front south of Tula, by the 2nd Panzer Army, while the 4th Army advanced directly towards Moscow from the west. According to Andrew Roberts, Hitler's offensive towards the Soviet capital was nothing less than an 'all-out attack': "It is no exaggeration to state that the outcome of the Second World War hung in the balance during this massive attack".
Initially, the Soviet forces conducted a strategic defence of the Moscow Oblast by constructing three defensive belts, deploying newly raised reserve armies, and bringing troops from the Siberian and Far Eastern Military Districts. As the German offensives were halted, a Soviet strategic counter-offensive and smaller-scale offensive operations forced the German armies back to the positions around the cities of Oryol, Vyazma and Vitebsk, and nearly surrounded three German armies. It was a major setback for the Germans, the end of the idea of a fast German victory in the USSR. Field Marshal Walther von Brauchitsch was excused as commander of OKH, instead Hitler appointed himself as Germany's supreme military commander as well.