Haile Selassie is a defining figure in modern Ethiopian history, and the key figure of Rastafari, a religious movement in Jamaica which emerged shortly after he became emperor in the 1930s. He attempted to modernize the country through a series of political and social reforms, including the introduction of Ethiopia's constitution of 1931, its first written constitution, and the abolition of slavery. He led the failed efforts to defend Ethiopia during the Second Italo-Ethiopian War and spent the period of Italian occupation in exile in England. In 1941, he returned to lead Ethiopia, after the British Empire defeated the Italian occupiers in the East African campaign.