Second World War: Allied forces halted the Axis invasion of Egypt at the First Battle of El Alamein.

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 Allies, formally referred to as the United Nations from 1942, were an international military coalition formed during World War II (1939–1945) to oppose the Axis powers. Its principal members were the "Big Four" – the United Kingdom, United States, Soviet Union, and China.

The Western Desert campaign took place in the deserts of Egypt and Libya and was the main theatre in the North African campaign of the Second World War. Military operations began in June 1940 with the Italian declaration of war and the Italian invasion of Egypt from Libya in September. Operation Compass, a five-day raid by the British in December 1940, was so successful that it led to the destruction of the Italian 10th Army over the following two months. Benito Mussolini sought help from Adolf Hitler, who sent a small German force to Tripoli under Directive 22. The Afrika Korps was formally under Italian command, as Italy was the main Axis power in the Mediterranean and North Africa.

The First Battle of El Alamein was a battle of the Western Desert campaign of World War II, fought in Egypt between Axis forces of the Panzer Army Africa—which included the Afrika Korps under Field Marshal Erwin Rommel—and Allied forces of the Eighth Army under General Claude Auchinleck.