Nobody called William Churchill was Prime Minister of Britain, though people with that name have been elected to the British Parliament. You may be referring to Winston Churchill, who was Prime Minister from 1940 to 1945 and again from 1951 to 1955.
Great Britain :)
Winston Churchill
Winston Churchill was prime Minister twice from 1940-1945 (WW2)and again from 1951-1955.
The Prime Minister of Britain during World War II was Winston Churchill.
Winston Churchill
Winston Churchill
Winston Churchill
Winston Churchill
Winston Churchill
Winston Churchill.
Winston Churchill
In June 1953 Winston Churchill was Prime Minister of Great Britain