Number 1 15-pounder Camel Battery RGA (today's 21 (Air Assault) Battery) served with six guns with the Indian Expeditionary Force in the Aden hinterland from 1915 to 1918 during the South Arabia campaign, to defend the important port at Aden against any Turkish advance. In July 1915, actions were fought in initially losing and then regaining the British advanced post at Sheik Othman controlling the water supply to Aden. Sgt Curtis was awarded the Distinguished Conduct Medal for saving his gun in these actions (presumably the first, in which two guns were lost). The Camel Battery was present when the British captured Hatum in January 1918.