WW2: King George VI, but there are many more Kings & even more wars.
George VI was king of Great Britain during World War 2.
Great Britain, or more correctly The United Kingdom of Great Britain and Northern Ireland, was involved in both World War 1 and World War 2.
Queen of where? If you're talking about Great Britain then it was KING George V
world war 1
There were many countries that were controlled by Great Britain at the beginning of World War 1.
George V ( reigned from 1910 to 1936 ) was King of Britain during World War 1.
King George V
Canada: William Lyon Mackenzie King. Great Britain: Winston Churchill
The whole war
Britain
Winston Churchill was the British Prime Minister for most of WWII. George VI was king.
World War 2 was of two alliances. The Axis, and the Allies. Great Britain and U.S.A were on the Allies side.