During the war, the Wiltshire's Territorial component would expand from one battalion to three. The 1/4th Wilts was called into service in 1914 as part of the South Western Brigade of the Wessex Division and dispatched to British India. For the next three years, it performed internal security duties in India until being transferred to Egypt in 1917. There it continued to perform security duties until joining the 233rd Brigade, later the 234th Brigade, of the 75th Division, part of the Egyptian Expeditionary Force. While serving with the 75th Division, 1/4th Wilts would see action at the Battle of Megiddo.