Who was the British Prime Minister at the outbreak of the Second World War?

Neville Chamberlain, a member of the Conservative Party, was the British Prime Minister at the outbreak of the Second World War. His policy of appeasement towards Nazi Germany, particularly regarding the territorial claims of Adolf Hitler, is often criticized. Chamberlain famously returned from the Munich Conference in 1938 proclaiming "peace for our time," as he believed he had secured peace by allowing Hitler to annex certain areas. However, when Germany invaded Poland on September 1, 1939, Britain and France declared war, and Chamberlain's leadership was soon replaced by Winston Churchill. Despite his efforts, Chamberlain's appeasement policy ultimately failed to prevent the escalation of global conflict in the form of World War II.