Elders with soldiers in the uniform of the Canadian Expeditionary Force. ca. 1916..... More than 7,000 Canadian First Nations, Inuit and Métis served with British forces during First World War and Second World War. When Canada declared war on Germany on September 10, 1939, the Aboriginal community quickly responded to volunteer. Four years later, in May 1943, the government declared that, as British subjects, all able Indian men of military age could be called up for training and service in Canada or overseas.