The Battle of Moscow (Russian: Битва за Москву, Romanized: Bitva za Moskvu) was the Soviet defense of Moscow and the subsequent Soviet counter-offensive that occurred between October 1941 and January 1942 on the Eastern Front of World War II against Nazi Germany forces. Adolf Hitler considered Moscow, which was the capital of the Union of Soviet Socialist Republics (USSR) and the largest Soviet city, to be the primary military and political objective for the Axis forces in their invasion of the Soviet Union. A separate German plan was codenamed Operation Wotan.
The original blitzkrieg invasion plan, which the Axis called Operation Barbarossa, had called for the capture of Moscow within three to four months. However, despite large initial advances, the Wehrmacht was soon slowed by Soviet resistance (in particular during the Battle of Smolensk, which lasted from July through September 1941 and delayed the German offensive towards Moscow for two months). Having secured Smolensk, the Wehrmacht was forced to consolidate its lines around Leningrad and Kiev, further delaying the drive towards Moscow. The Axis advance was finally renewed on September 30, 1941, with an offensive codenamed Operation Typhoon, the goal of which was the capture of Moscow before the onset of winter.
After a successful initial advance leading to the encirclement and destruction of several Soviet armies, the German offensive was stopped by Soviet resistance at the Mozhaisk defensive line, just 120 km (75 mi) from the capital. Having penetrated the Soviet defenses, the Wehrmacht offensive was slowed by weather conditions, with autumn rains turning roads and fields into thick mud that significantly impeded Axis vehicles, horses, and soldiers. Although the onset of colder weather and the freezing of the ground allowed the Axis advance to continue, it continued to struggle in the face of the severe cold and stiffening Soviet resistance.
By early December, the lead German Panzer Groups stood less than 30 kilometers (19 mi) from the Kremlin, and Wehrmacht officers were able to see some of Moscow's buildings with binoculars; but, handicapped by cold and exhausted troops, the Axis forces were unable to make further advances. On December 5, 1941, fresh Soviet Siberian troops, prepared for winter warfare, attacked the German forces in front of Moscow; by January 1942, the Wehrmacht had been driven back 100 to 250 km (60 to 150 mi), ending the immediate threat to Moscow and marking the closest that Axis forces ever got to capturing the Soviet capital.
The Battle of Moscow is usually considered one of the most important battles in the war between the Axis Powers and the USSR, primarily because the Soviets were able to successfully prevent the most serious attempt to capture their capital. The battle was also one of the largest during World War II, with more than a million total casualties. It marked a turning point as it was the first time since the Wehrmacht began its conquests in 1939 that it had been forced into a major retreat. The Wehrmacht had been forced to retreat earlier during the Yelnya Offensive in September 1941 and at the Battle of Rostov (1941) (which led to von Rundstedt losing command of German forces in the East), but these retreats were minor compared to the one at Moscow.