The 15th Cavalry Brigade was a brigade-sized formation that served alongside British Empire forces in the Sinai and Palestine Campaign, during World War I. Originally called the Imperial Service Cavalry Brigade it was formed from Imperial Service Troops provided by the Indian Princely States of Jodhpur, Hyderabad, Mysore, Patiala and Alwar which each provided a regiment of lancers. A maximum of three regiments served in the brigade at any one time. The states of Kashmir, Idar and Kathiawar provided smaller detachments for the brigade, which was at times reinforced by other British Empire regiments and artillery batteries when on operations.