World War II: The German army launches its offensive to encircle several Soviet armies near Smolensk.

World War II or the Second World War was a global conflict between two coalitions: the Allies and the Axis powers. Nearly all of the world's countries participated, with many nations mobilising all resources in pursuit of total war. Tanks and aircraft played major roles, enabling the strategic bombing of cities and delivery of the first and only nuclear weapons ever used in war. World War II is the deadliest conflict in history, causing the death of 70 to 85 million people, more than half of whom were civilians. Millions died in genocides, including the Holocaust, and by massacres, starvation, and disease. After the Allied victory, Germany, Austria, Japan, and Korea were occupied, and German and Japanese leaders were tried for war crimes.

The first Battle of Smolensk was a battle during the second phase of Operation Barbarossa, the Axis invasion of the Soviet Union, in World War II. It was fought around the city of Smolensk between 10 July and 10 September 1941, about 400 km (250 mi) west of Moscow. The Ostheer had advanced 500 km (310 mi) into the USSR in the 18 days after the invasion on 22 June 1941.

Smolensk is a city and the administrative center of Smolensk Oblast, Russia, located on the Dnieper River, 360 kilometers (220 mi) west-southwest of Moscow.