Winston Churchill didn't become British Prime Minister until 10 May 1940. War was declared by his predecessor Neville Chamberlain on 3 September 1939.
He didn't. It was Neville Chamberlain that declared war with Germany.
Avalon
The resignation of Neville Chamberlain.
Winston Churchill was Prime Minister of Britain during WW2.
Prime minister of Great Britain
He was Prime Minister of Britain at the time.
Winston Churchill
Winston Churchill was not the president, he was the Prime Minister, he declared war on Germany
Winston Churchill
Hitler declared war on the USA on 11 December 1941, during a Reichstag speech in Berlin.
"Never, never, never, never, never give up." ~ Winston Churchill. He said this during World War II, "My people, never, never, never, never, never give up." The people got inspired. They won the war.
With WW 2 in mind, Winston Churchill gave Great Britain magnificent leadership. He maintained British morale in the worst times of the war and his cooperation with the US was vital to winning the war on the western front.