Second Italo-Ethiopian War

The Second Italo-Ethiopian War was fought from 1935 to 1937 after Fascist Italy under Benito Mussolini invaded the Ethiopian Empire, one of the last independent states in Africa, seeking colonial expansion and revenge for Italy's earlier defeat at Ethiopian hands at the Battle of Adwa in 1896. Italian forces under Marshal Pietro Badoglio made extensive and documented use of chemical weapons, including mustard gas, against Ethiopian troops and civilians in direct violation of the 1925 Geneva Protocol, helping to overcome Ethiopia's poorly equipped defenders despite the personal leadership of Emperor Haile Selassie. Addis Ababa fell in May 1936, after which Italy declared Ethiopia annexed and merged it with Eritrea and Italian Somaliland into the colony of Italian East Africa, though scattered Ethiopian resistance continued in the countryside. The League of Nations condemned the invasion and imposed limited economic sanctions on Italy, but its failure to halt the war exposed the League's weakness and is widely seen as a key step toward the collapse of the interwar collective-security system before the Second World War.