Courtesy of the Library of Parliament, here are the top 10 longest-serving MPs in Canadian political history, along with their political affiliation and brief sketches:

Prime Minister Wilfrid Laurier (Liberal, Laurier Liberal)

First elected: Jan. 22, 1874.

Left office: Feb. 17, 1919 (death).

Length of service: 44 years, 10 months, 17 days.

Portfolios held: Prime Minister (1896-1911), Acting Minister of Marine and Fisheries, Interior and Superintendent-General of Indian Affairs 1905), President of the Privy Council (1896), Minister Inland Revenue (1877).

Also served as Leader of the Official Opposition from 1887-1896 and 1911 to 1919.

John Graham Haggart (Conservative)

First elected: Oct. 12, 1872.

Left office: March 13, 1913 (death).

Length of service: 40 years, 4 months, 19 days.

Portfolios held: Minister of Railways and Canals (1892-1896), Postmaster General (1888-1892).

Herbert Gray (Liberal)

First elected: June 18, 1962.

Left office: Jan. 14, 2002 (retired).

Length of service: 39 years, 6 months, 29 days.

Portfolios held: Minister responsible for the Millennium Bureau (1998-2002), Leader of the Government in the House of Commons (1993-1997), Solicitor General (1993-1997), President of the Treasury Board (1982-1984), Minister of Regional Economic Expansion (1982), Minister of Industry, Trade and Commerce (1980-1982). Minister of Consumer and Corporate Affairs (1972-1974), Minister of National Revenue (1970-1972), Minister Without Portfolio (1969-1970)

Also served as Acting Leader of the Official Opposition in 1990.

Prime Minister John Diefenbaker (Conservative, Progressive Conservative)

First elected: March 26, 1940.

Left office: Aug. 16, 1979 (death).

Length of service: 39 years, 4 months, 22 days.

Portfolios held: Prime Minister (1957-1963), President of the Privy Council (1962-1963), Secretary of State for External Affairs (1957-1959).

Two separate terms as Leader of the Official Opposition — from 1956 to 1957 and 1963 to 1967.

John Costigan (Liberal-Conservative, Liberal)

First elected: Sept. 20, 1867.

Left office: Jan. 14, 1907 (called to the Senate).

Length of service: 39 years, 3 months, 25 days — plus an additional ten years in the Senate.

Portfolios held: Minister of Trade and Commerce (1896), Minister of Marine and Fisheries ((1894-1896), Secretary of State (1892-1894), Minister of Inland Revenue (1882-1892).

William Paterson (Liberal)

First elected: Oct. 12, 1872.

Left office: Sept. 20, 1911 (defeated).

Length of service: 38 years, 9 months, 7 days.

Portfolios held: Controller/Minister of Customs (1896-1911).

Ernest Lapointe (Liberal, Laurier Liberal)

First elected: Feb. 12, 1904.

Left office: Nov. 26, 1941 (death).

Portfolios held: Minister of Justice and Attorney General (1924-1930, 1935-1941), Minister of Marine and Fisheries (1921-1924).

Charles Gavan Power (Laurier Liberal, Liberal)

First elected: Dec. 17, 1917.

Left office: July 27, 1955 (called to the Senate).

Length of service: 37 years, 7 months, 10 days — plus an additional thirteen years in the Senate.

Portfolios held: Minister of Pensions and National Health (1935-1939) Postmaster General (1939-1940), Minister of National Defence for Air (1940-1944).

Stanley Knowles (Co-operative Commonwealth Federation, New Democratic Party)

First elected: Nov. 30, 1942.

Left office: Sept. 3, 1984 (retired).

Length of service: 37 years, 6 months, 18 days.

Positions held: New Democratic Party House Leader (1962-1984).

Upon his retirement in 1984, Prime Minister Pierre Trudeau appointed him an honorary officer of parliament.

Thomas Sproule (Conservative)

First elected: Sept. 17, 1878.

Left office: Dec. 2, 1915 (called to the Senate).

Length of service: 37 years, 2 months, 16 days — plus just under two additional years in the Senate.

Positions held: Speaker of the House of Commons (1911-1915).

Data courtesy of the Library of Parliament