First World War: The Battle of Passchendaele began near Ypres, Belgium, with the Allies aiming to force German troops to withdraw from the Channel Ports.

World War I or the First World War, also known as the Great War, was a global conflict between two coalitions: the Allies and the Central Powers. Main areas of conflict included Europe and the Middle East, as well as parts of Africa and the Asia-Pacific. There were important developments in weaponry including tanks, aircraft, artillery, machine guns, and chemical weapons. One of the deadliest conflicts in history, it resulted in an estimated 30 million military casualties, plus another 8 million civilian deaths from war-related causes and genocide. The movement of large numbers of people was a major factor in the deadly Spanish flu pandemic.

The Third Battle of Ypres, also known as the Battle of Passchendaele, was a campaign of the First World War, fought by the Allies against the German Empire. The battle took place on the Western Front, from July to November 1917, for control of the ridges south and east of the Belgian city of Ypres in West Flanders, as part of a strategy decided by the Entente at conferences in November 1916 and May 1917. Passchendaele lies on the last ridge east of Ypres, 5 mi (8 km) from Roulers, a junction of the Bruges-(Brugge)-to-Kortrijk railway. The station at Roulers was on the main supply route of the German 4th Army. Once Passchendaele Ridge had been captured, the Allied advance was to continue to a line from Thourout to Couckelaere (Koekelare).

Ypres is a Belgian city and municipality in the province of West Flanders. Though the Dutch name Ieper is the official one, the city's French name Ypres is most commonly used in English. The municipality comprises the city of Ypres/Ieper and the villages of Boezinge, Brielen, Dikkebus, Elverdinge, Hollebeke, Sint-Jan, Vlamertinge, Voormezele, Zillebeke, and Zuidschote. Together, they are home to about 34,900 inhabitants.