England. Twice, at two different times. First he was the PM during WWII, shortly after the war got started in Europe. Then he was elected PM again in the 1950s when it became clear that there was a "Cold War" between the capitalist, democratic West the forces of communism.
10th May 1940 -> 26th July 1945
and
26th October 1951 -> 7th April 1955
May 10th 1940 when Chamberlain resigned & again when the Conservatives won the General Election in 1951.
Winston Churchill.
Winston Churchill was the Prime Minster of England during WWII. England was part of the Ally forces not the Axis powers.
1939 to 1940, Prime Minster Neville Chamberlain. 1940 to 1945, Prime Minster Winston Churchill.
Chamberlain, Prime Minster: 1937- May 1940. Churchill, Prime Minister: May 1940-1945 and 1951-55.
Winston Churchill was Prime Minister of the United Kingdom which includes England.
Great Britain
Neville Chamberlain until 10 May and then Winston Churchill
Winston Churchill became Prime Minister in May 1940
Because he was prime minster of Great Britain during WW2
Neville Chamberlain was the Prime Minister of Britain between 28th May 1937 and 10th May 1940, he was succeeded by Sir Winston Churchill, Churchill was Prime Minster between 10th May 1940 and 26th July 1945.
Winston Churchill was democratically elected by the British electorate, he was Prime Minster of the United Kingdom of Great Britain and Northern Ireland.