John George Diefenbaker was the 13th prime minister of Canada, serving from 1957 to 1963. He was the only Progressive Conservative party leader between 1930 and 1979 to lead the party to an election victory, doing so three times, although only once with a majority of the seats in the House of Commons.

The King's Privy Council for Canada, sometimes called His Majesty's Privy Council for Canada or simply the Privy Council (PC), is the full group of personal consultants to the monarch of Canada on state and constitutional affairs. Practically, the tenets of responsible government require the sovereign or his viceroy, the governor general of Canada, to almost always follow only that advice tendered by the Cabinet: a committee within the Privy Council composed usually of elected members of Parliament. Those summoned to the KPC are appointed for life by the governor general on the advice of the prime minister of Canada, meaning that the group is composed predominantly of former Cabinet ministers, with some others having been inducted as an honorary gesture. Those in the council are accorded the use of an honorific style and post-nominal letters, as well as various signifiers of precedence.