Answer
Percival's most noted defeat, the Battle of Singapore, took place in 1942. He was appointed the commander-in-chief of the British Far East Command in February 1941 and was responsible for the defence of Singapore. However, the Japanese launched a surprise attack on the island in December 1941 and the British forces were quickly overwhelmed. Percival surrendered to the Japanese on 15 February 1942 and Singapore fell.