 On 18 December 1914, the Camerons received authority to raise a complete battalion for overseas service and the Volunteer Overseas Battalion was gazetted and mobilization commenced under command of Lieutenant-Colonel Robert M. Thomson.The battalion began training at Minto Armoury in Winnipeg and was soon re-designated the 43rd Battalion (Cameron Highlanders of Canada), CEF.On 29 May 1915 the battalion entrained for Montreal and deployment overseas.