17 April 1923
From the 16th century right up to the 19th, slaves from Ethiopia were sold across the world. However, the slave trade within Ethiopia was very much different from that observed in the West. The slave trade in Ethiopia was slightly more humane than the one in western countries. It was also influenced by religion; there were certain rules that applied only to Christians and others that only applied to Muslims. Emperor Haile Selassie put an end to the trade when he abolished the practice in 1923. He quickly strived to modernise Ethiopia and led the country to become a member of the League of Nations, the forerunner to the United Nations (UN).
References

African Holocaust, Ethiopian Slave Trade, from African Holocaust, [online], Available at www.africanholocaust.net [Accessed: 16 April 2014]|Imperial Ethiopia, Reflections on Haile Selassie from Imperial Ethiopia, [online], Available at www.imperialethiopia.org [Accessed: 16 April 2014]