The Canadian Army Service Corps was established by General Order # 141 in the Non-Permanent Active Militia on 1 November 1901 and in the Permanent Active Militia in 1903. The Canadian Permanent Army Service Corps was redesignated The Royal Canadian Army Service Corps on 3 Nov 1919.
The CASC was modelled directly off the British Army Service Corps to provide all transportation and supply services to the Army. Initially, the CASC consisted of four companies to support the Active Militia units. By the summer of 1914 the CASC had a strength of 3000 personnel in eighteen companies, including #11 Service Company in Winnipeg (stood up 1907) and #18 Service Company in St. James (stood up 1912).
During the First World War, over 17,000 CASC members provided a support element for each Canadian Division, and later on, for the Canadian Corps. With the introduction of motorized vehicles, the CASC carried commodities of a greater range and of greater weights. Motorized transportation also resulted in expanded responsibilities such as driving ambulances and engineer pontoon vehicles, carrying all natures of ammunition, and mobile repair and recovery.
The main duties of the Canadian Army Service Corps (CASC) in France centered on the transport and supply of food, forage, ammunition, equipment, clothing and engineering material and stores. Corps personnel also repaired motor vehicles and each division had an ambulance repair workshop. In England, the CASC were also responsible for feeding the troops.
In recognition of the services rendered by the C.A.S.C. during the Great War, His Majesty King George V authorized the designator “Royal” in 1919.