The 7th Battalion was formed in Bristol in August 1914. It sailed to the island of Lemnos in June 1915 as part of the 39th Brigade in the 13th (Western) Division and went into the line at Gallipoli the next month. The battalion fought its first action on 8 August in the Battle of Chunuk Bair, during which it suffered over 820 casualties, including all of its officers, warrant officers and senior non-commissioned officers. It was brought back up to strength and moved to Egypt in January 1916. In March, the 13th Division was transferred to Mesopotamia, but on landing at Basra the battalion was put out of action by an outbreak of relapsing fever. It rejoined the division in the middle of April and fought in the unsuccessful attempt to lift the siege of Kut. The battalion saw action in December 1916 and February 1917 during the subsequent advance on and capture of Kut, and fought its last battle on 29 March 1917 during the Samarrah offensive. It spent the next 15 months mostly on defensive and garrison duties and was disbanded in September 1919.