The Minister of National Defence is a Minister of the Crown and is the Canadian politician within the Cabinet of Canada responsible for the management and direction of all matters relating to the national defence of Canada. The Department of National Defence is headed by the Deputy Minister of National Defence, the Department’s senior civil servant, while the Canadian Armed Forces are headed by the Chief of the Defence Staff, Canada’s senior serving military officer. Both are responsible to the Minister. The Queen of Canada (represented by the Governor General of Canada) is the Commander-in-Chief of the Canadian Armed Forces and has final authority on all orders and laws for the "defence of the realm" (see Queen-in-Council). The minister is responsible, through the tenets of responsible government, to Parliament for "the management and direction of the Canadian Forces". Any orders and instructions for the Canadian Armed Forces are issued by or through the Chief of the Defence Staff. The Department of National Defence exists to aid the minister in carrying out his responsibilities, and acts as the civilian support system for the Canadian Forces.