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
South West Africa land taken from the northern border of Bechuanaland, extending as far as the Zambezi river, was added to the colony. It was named the Caprivi Strip ("Caprivizipfel") after the German Chancellor Leo von Caprivi. In 1915, during South West Africa Campaign of World War I, South Africa captured the German colony. After the war, it was declared a League of Nations Class C Mandate territory under the Treaty of Versailles, with the Union of South Africa responsible for the administration of South West Africa. From 1922, this included Walvis Bay, which, under the South West Africa Affairs Act, was governed