During World War II, the Imperial Japanese Army invaded British Malaya, culminating in the Battle of Singapore. The British were defeated, surrendering on 15 February 1942. British Prime Minister Winston Churchill called this "... the worst disaster and largest capitulation in British history".[18] The Sook Ching massacre of ethnic Chinese after the fall of Singapore claimed between 5,000 and 25,000 lives.[19] The Japanese occupied Singapore until the British repossessed it in September 1945, after the Surrender of Japan.[20]
Singapore's first general election in 1955 was won by David Marshall, the pro-independence leader of the Labour Front. He led a delegation to London to demand complete self-rule but was turned down by the British. He subsequently resigned and was replaced by Lim Yew Hock, whose policies convinced Britain to grant Singapore full internal self-government for all matters except defence and foreign affairs.[21]