Second World War: The British Army carried out Operation Collar, its first commando raid into German-occupied France.

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 British Army is the principal land warfare force of the United Kingdom. As of 1 January 2025, the British Army comprises 73,847 regular full-time personnel, 4,127 Gurkhas, 25,742 volunteer reserve personnel and 4,697 "other personnel", for a total of 108,413.

Operation Collar was the codeword for the first commando raid conducted by the British forces during the Second World War. The location selected for the raid was the Pas-de-Calais department on the French coast. The British Commandos had not long been formed and were not yet trained and the operation was given to No. 11 Independent Company under the command of Major Ronnie Tod.

A commando is a combatant, or operative of an elite light infantry or special operations force, specially trained for carrying out raids and operating in small teams behind enemy lines.