Declaration of war by Canada
A declaration of war by Canada is a formal declaration issued by the Government of Canada (the federal Crown-in-Council) indicating that a state of war exists between Canada and another nation. It is an exercise of the Royal Prerogative on the constitutional advice of the ministers of the Crown in Cabinet and does not require the direct approval of the Parliament of Canada, though such can be sought by the government. Since gaining the authority to declare war under the Statute of Westminster 1931, Canada has declared war only during the Second World  War. Second World War. Nazi Germany. After Nazi Germany invaded Poland on September 1, 1939, the United Kingdom and France declared war on September 3. To assert Canada's independence from the UK, as already established by the Statute of Westminster 1931, Canada's political leaders decided to seek the approval of the federal parliament to declare war. Parliament was not scheduled to return until October 2, but returned to session early on September 7 to consider the declaration of war. On September 9, the House of Commons and Senate approved authorization for a declaration of war. The Cabinet then  drafted an Order in Council to that effect. On September 10, Vincent Massey, Canada's High Commissioner to the United Kingdom, brought the document to King George VI, at the Royal Lodge, Windsor Great Park, for his signature, whereupon Canada had officially declared war on Germany. In his capacity as the government's official recorder for the war effort, Leonard Brockington noted: " did not ask us to declare war for him—we asked King George VI of Canada to declare war for us." Fascist Italy. On June 10, 1940, Italy declared war on France and the United Kingdom. Canadian National  Defence Minister Norman Rogers had been killed in a plane crash that day. Both houses of parliament approved a declaration of war and the Cabinet issued the Order in Council the same day. It was submitted to the King and the proclamation was read by the Prime Minister to parliament the following day. Finland, Hungary, Romania. Parliament adjourned on November 14, 1941, and was not scheduled to return until January 21, 1942. At the urging of the Soviet Union, the United Kingdom declared war on Finland on December 6, 1941. At the UK's urging, the Canadian Cabinet the next  day issued a proclamation declaring war on Finland, Hungary, and Romania. Japan. On December 7, 1941 (December 8 in Japan), the Empire of Japan began an undeclared war upon the United Kingdom (invading Hong Kong and Malaya), Canada, and the United States (attacking Pearl Harbor). Mackenzie King and the Cabinet decided to go to war with Japan that evening and issued a proclamation the following day declaring that, as of December 7, a state of war existed between Japan and Canada. One day later, the US and UK also declared war on the Japanese Empire. These proclamations were presented by  Mackenzie King to the House of Commons when parliament returned on January 21, 1942.