World War II: Rotterdam, Netherlands is bombed by the Luftwaffe of Nazi Germany despite a ceasefire, killing about 900 people and destroying the historic city center.

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.

Rotterdam is the second-largest city in the Netherlands after the national capital of Amsterdam. It is in the province of South Holland, part of the North Sea mouth of the Rhine–Meuse–Scheldt delta, via the New Meuse inland shipping channel, dug to connect to the Meuse at first and now to the Rhine.

In 1940, Rotterdam was subjected to heavy aerial bombardment by the Luftwaffe during the German invasion of the Netherlands during the Second World War. The objective was to support the German troops fighting in the city, break Dutch resistance and force the Dutch army to surrender. Bombing began at the outset of hostilities on 10 May and culminated with the destruction of the entire historic city centre on 14 May, an event sometimes referred to as the Rotterdam Blitz. According to an official list published in 2022, at least 1,150 people were killed, with 711 deaths in the 14 May bombing alone, and 85,000 more were left homeless.

The Luftwaffe was the aerial-warfare branch of the Wehrmacht before and during World War II. Germany's military air arms during World War I, the Luftstreitkräfte of the Imperial Army and the Marine-Fliegerabteilung of the Imperial Navy, had been disbanded in May 1920 in accordance with the terms of the 1919 Treaty of Versailles, which banned Germany from having any air force.