Siege of Saïo the Italian dictator, Benito Mussolini, proclaimed the colony of "Africa Orientale Italiana" (AOI, Italian East Africa), formed from Ethiopia (after the Italian victory in the Second Italo-Ethiopian War, fought 3 October 1935 – May 1936) and the existing Italian possessions of Italian Eritrea and Italian Somaliland. On 10 June 1940, Mussolini declared war on Britain and France, which made Italian military forces in Libya a threat to Egypt and those in Italian East Africa a danger to the British and French colonies in East Africa. Italian belligerence also closed the Mediterranean to Allied merchant ships and endangered British supply routes
Italian East Africa answerable to a viceroy, who in turn represented the Emperor. Italian East Africa was briefly enlarged in 1940, as Italian forces conquered British Somaliland, thereby bringing all Somali territories under Italian administration. However, the enlarged colony was dismembered only a year later, when in the course of the East African Campaign the colony was occupied by British forces. Italian East Africa, in Italian "Africa Orientale Italiana", was acronymed in official documents as "AOI". The dominion was formed in 1936, after the Second Italo-Abyssinian War that resulted in the annexation of the Ethiopian Empire by Fascist Italy, by merging the pre-existing