A History of the English-Speaking Peoples out and then when Churchill was appointed Prime Minister. After the war ended in 1945, Churchill was busy, first writing his history of that conflict and then as Prime Minister again between 1951 and 1955, and so it was not until the late 1950s, when Churchill was in his early eighties, that he was able to finish the work. The later volumes were completed when Churchill was over eighty. A full one-third of the last volume was devoted to the military minutiae of the American Civil War. Social history, the agricultural revolution, and the industrial revolution hardly get a mention.
Prime minister could command the loyalty of the Commons was increasingly necessary. The long tenure of the wartime prime minister William Pitt the Younger (1783–1801), combined with the mental illness of George III, consolidated the power of the post. The title was first referred to on government documents during the administration of Benjamin Disraeli but did not appear in the formal British Order of precedence until 1905. The prestige of British institutions in the 19th century and the growth of the British Empire saw the British model of cabinet government, headed by a prime minister, widely copied, both in other European countries