World War II began in Europe on September, 1st 1939, and the Parliament of Canada declared war between Canada and Germany on September 10, 1939. The same day, the Patricias were mobilized for active service. The regiment recruited in Winnipeg and Vancouver until October. The regiment sailed from Halifax, Nova Scotia on the December 21, 1939, arriving in Aldershot, England, as part of the 2nd Brigade of the 1st Canadian Infantry Division under the command of Lieutenant Colonel W.G. Colquhoun. They spent New Year's Eve in Cove, west of Farnborough. On February 10, 1940, the colonel-in-chief, Princess Patricia, inspected her regiment for the first time in twenty-one years. The regiment spent three and a half years in United Kingdom, most of which was spent in coastal defence and training in various parts of the country.