World War II: German troops began Operation Winter Storm, an attempt to relieve encircled Axis forces during the Battle of Stalingrad.

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.

Operation Winter Storm, a German offensive in December 1942 during World War II, involved the German 4th Panzer Army failing to break the Soviet encirclement of the German 6th Army during the Battle of Stalingrad.

The Axis powers, originally called the Rome–Berlin Axis and also Rome–Berlin–Tokyo Axis, was the military coalition which initiated World War II and fought against the Allies. Its principal members were Nazi Germany, Kingdom of Italy and the Empire of Japan. The Axis were united in their far-right positions and general opposition to the Allies, but otherwise lacked comparable coordination and ideological cohesion.

The Battle of Stalingrad was a major battle on the Eastern Front of World War II, beginning when Nazi Germany and its Axis allies attacked and became locked in a protracted struggle with the Soviet Union for control over the Soviet city of Stalingrad in southern Russia. The battle was characterized by fierce close-quarters combat and direct assaults on civilians in aerial raids; the battle epitomized urban warfare, and it was the single largest and costliest urban battle in military history. It was the bloodiest and fiercest battle of the entirety of World War II—and arguably in all of human history—as both sides suffered tremendous casualties amidst ferocious fighting in and around the city. The battle is commonly regarded as the turning point in the European theatre of World War II, as Germany's Oberkommando der Wehrmacht was forced to withdraw a considerable amount of military forces from other regions to replace losses on the Eastern Front. By the time the hostilities ended, the German 6th Army and 4th Panzer Army had been destroyed and Army Group B was routed. The Soviets' victory at Stalingrad shifted the Eastern Front's balance of power in their favour, while also boosting the morale of the Red Army.