World War I: Field Marshal Allenby captures Jerusalem from the Ottoman Empire.

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.

Field Marshal Edmund Henry Hynman Allenby, 1st Viscount Allenby, was a senior British Army officer and imperial governor. He fought in the Second Boer War and in the First World War, in which he led the British Empire's Egyptian Expeditionary Force (EEF) during the Sinai and Palestine Campaign against the Ottoman Empire in the conquest of Palestine.

The Battle of Jerusalem also known as the Fall of Jerusalem occurred during the British Empire's "Jerusalem Operations" against the Ottoman Empire, in World War I, when fighting for the city developed from 17 November, continuing after the surrender until 30 December 1917, to secure the final objective of the Southern Palestine Offensive during the Sinai and Palestine Campaign of World War I. Before Jerusalem could be secured, two battles were recognised by the British as being fought in the Judean Hills to the north and east of the Hebron–Junction Station line. These were the Battle of Nebi Samwill from 17 to 24 November and the Defence of Jerusalem from 26 to 30 December 1917. They also recognised within these Jerusalem Operations, the successful second attempt on 21 and 22 December 1917 to advance across the Nahr el Auja, as the Battle of Jaffa, although Jaffa had been occupied as a consequence of the Battle of Mughar Ridge on 16 November.