The Second Italo-Ethiopian War was to be Mussolini's way of making up for Italy's embarrassing defeat at the hands of the Ethiopians in the First Italo-Ethiopian War in 1896, and was also a chance to expand the Italian empire by taking one of the last regions of Africa not controlled by other European powers and divert the populace from economic woes. General Emilio de Bono put on record that preparations for the invasion of Ethiopia (Abyssinia) had been going on since 1932 as roads were being built from Italian Somaliland into Ethiopian territory, though Mussolini constantly claimed that he was not a "collector of deserts" and would never think of invading. Ethiopians protested this build-up to war which eventually led up to a border clash at Walwal. Mussolini called this clash "unprovoked aggression" by Ethiopia and Italian forces invaded on 3 October 1935, led by de Bono. In only three days the Italians had captured Adwa by committing the world's first mass aerial bombardment of civilians. In December Pietro Badoglio replaced de Bono as commander of the invasion because of de Bono's cautious advance. In violation of the Geneva convention, the Italian military committed war crimes by extensively using chemical warfare against the Ethiopian military and, even more so, against Ethiopian civilians as well as attacking Ethiopian, British, and Swedish Red Cross facilities. On 31 March 1936, a desperate final counter-attack by Emperor Haile Selassie I of Ethiopia, was carried out, though word of the attack had already gotten to the Italians, giving them victory in the Battle of Maychew again through the use of chemical weapons. Only a few days later the Ethiopian capital Addis Ababa was conquered, allowing Italy to annex the country on 7 May, proclaiming Victor Emmanuel III Emperor of Ethiopia. Italy's East African possessions was unified into the colony of Italian East Africa.
