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 Staff) had planned for a war after 1942. In the summer of 1940, Italy was far from ready for a long war or for the occupation of large areas of Africa. Hostilities began on 13 June 1940, with an Italian air raid on the base of 1 Squadron Southern Rhodesian Air Force (237 (Rhodesia) Squadron RAF) at Wajir in the East Africa Protectorate (Kenya). In August 1940, the protectorate of British Somaliland was occupied by Italian forces and absorbed into Italian East Africa. This occupation lasted around six months. By early 1941, Italian forces had been largely pushed back from