When William Lyon Mackenzie King retired in 1948, he had held office as Prime Minister of Canada for a total of 7829 days, a longer term of service than that of any other Prime Minister in the history of the British Commonwealth. Like Roosevelt, his contemporary of many momentous years, he was greatly admired and greatly hated, but none dispute the tremendous influence he exerted on the history of his country, or, indeed, his place in world history...