The wedding of Princess Elizabeth to Philip Mountbatten on November 20, 1947, was commemorated by both British and Canadian Post Offices. Since the wedding announcement was made on July 9, 1947, the British Post Office did not issue a commemorative stamp because there was insufficient time to prepare an issue. Instead, a slogan postmark was made for use from November 20 to the end of November. The Canadian Post Office issued a commemorative stamp for the wedding, but only after the event, in February, 1948.”
The CANADIAN DESIGN RESOURCE