During each of the World Wars, the British Prime Minister changed. In the First World War, Herbert Asquith, Prime Minister from 1908, was succeeded by David Lloyd George in 1916. In the Second World War, Neville Chamberlain, Prime Minister from 1937, was succeeded by Winston Church in 1940.

The successors were both men free from ideology. Lloyd George, eleven years the senior of the two men, might espouse a cause that brought him publicity, only to cast it aside as soon as his personal priorities shifted. Churchill, who served with Lloyd George in the Liberal government before the Great War, became a Conservative in the post-war years. Defeated in the general elections of 1945 and 1951, he became part of the post-war consensus, administering the new society created by the 1945 Labour government.

Both men could be individualist in their stance, contrarian in their approach to political issues. Both men could attract vilification from their opponents and could become lonely backbench figures.

Lloyd George remained a white-maned man of a former age lurking on the opposition benches for more than two decades after being ousted as Prime Minister in 1922.

The disaster of the 1915 Gallipoli Campaign caused Churchill to resign from the government and to return to duty on the Western Front, where his service included thirty-six night time raids into No Man’s Land. He remained an outsider, a critic of the 1930s policies of appeasement. Even when he had returned to the government as First Lord of the Environment in 1939, there was no certainty he would become Prime Minister when Chamberlain resigned in May 1940.

Both men were able to rise to power and to lead the country in times of crisis because they both possessed the genius necessary to create coalitions from disparate elements. After the 1918 general election, David Lloyd George led a coalition comprised overwhelmingly of Conservative members of parliament. In 1940, Churchill formed a government which spanned the political spectrum and included Labour politicians Attlee, Greenwood, Bevin and Wilkinson.

If there are lessons to be learned from wartime  Prime Ministers, they are that the most effective response to a crisis is not the politics of confrontation, but the creation of broad-based alliances. Lloyd George and Churchill both brought opponents into positions of high office. Arthur Balfour, Conservative Prime Minister from 1902-1905 became Foreign Secretary in Lloyd George’s government. Clement Attlee, Leader of the Opposition from 1935-40 and Prime Minister from 1945, served as deputy Prime Minister under Churchill.

Loyalty to the government and a spirit of national unity was created by political leaders who understood how to bring people together.

A Prime Minister who has written a biography of Churchill should know what is needed.