December 29, 1921 - June 28, 1926
September 25, 1926 - August 7, 1930
October 23, 1935 - November 15, 1948
William Lyon Mackenzie King (Liberal Party of Canada) is the longest serving Prime Minister in Canadian history having served three terms in office from December 29, 1921, to June 28, 1926, from September 25, 1926, to August 7, 1930, and from October 23, 1935, to November 15, 1948.
Some key accomplishments of his terms include the creation of old age pensions in 1926, unemployment insurance in 1940, family allowances in 1944, and his leadership of Canada through World War II from 1939 to 1945. He also appointed the first woman to the Senate in 1930.
In addition to his several terms as Prime Minister, Mr. King served as Canada's Secretary of State for External Affairs several times between 1921 and 1946. He was Leader of the Opposition in the House of Commons from 1919 to 1921 and in 1926. He was first elected to the House of Commons in 1908 and was a lawyer by profession.
William Lyon Mackenzie King was born in Berlin (now Kitchener), Ontario, on December 17, 1874, and died in Kingsmere, Quebec, on July 22, 1950.