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
British military post offices in Africa declared that the remaining overprinted stamps were valid for postage throughout the UK, and so many of the surviving stamps have British inland rather than foreign postmarks. The East Africa Forces in Italian Somalia also received British stamps, but overprinted "E.A.F." instead, beginning 15 January 1943. From 1948 on, the military administrations in Eritrea, Somalia, and Tripolitania used their own overprints. British military post offices in Africa The British post offices in Africa were a system of post offices set up by the United Kingdom to be used by its Middle East Forces and East Africa Forces in Africa during