W. L. Mackenzie King (1874-1950) was Canada's longest-serving, best-known and certainly most unusual prime minister. The keeper of a famous series of candid personal diaries, he is a gift to the biographer. King did not live long enough to write his planned memoirs, and his official biography remains long unfinished. As a result, some 24 biographies of him have been published, with different purposes and from different perspectives. They are a study in extreme contrasts. This is a critical collective history of those works, published between 1922 and 2014.