The Ethiopian Empire was invaded by Italy on 3 October 1935. On 2 May 1936, Emperor Haile Selassie I fled into exile, just before the Italian occupation on 7 May. After the outbreak of World War II, the Ethiopian government-in-exile cooperated with the British during the British Invasion of Italian East Africa beginning in June 1940. Haile Selassie returned to his rule on 18 January 1941. Ethiopia declared war on Germany, Italy and Japan in December 1942.