Haile Selassie was crowned 2 November 1930 with the titles King of Kings, Lord of Lords, Conquering Lion of the Tribe of Judah, Elect of God and Power of the Trinity. He is seen by the Rastafari as Jah incarnate.
The early 20th century was marked by the reign of Emperor Haile Selassie I, who came to power after Iyasu V was deposed. It was he who undertook the modernization of Ethiopia, from 1916, when he was made a Ras and Regent (Inderase) for Zewditu I and became the de facto ruler of the Ethiopian Empire. Following Zewditu's death he was made Emperor on 2 November 1930.
Haile Selassie was born from parents of three Ethiopian ethnicities: the Oromo and Amhara, which are the country's two main ethnic groups, as well as the Gurage.
The independence of Ethiopia was interrupted by the Second Italo-Abyssinian War and Italian occupation (1936–1941). During this time of attack, Haile Selassie appealed to the League of Nations in 1935, delivering an address that made him a worldwide figure, and the 1935 Time magazine Man of the Year. Following the entry of Italy into World War II, British Empire forces, together with patriot Ethiopian fighters, officially liberated Ethiopia in the course of the East African Campaign in 1941, while an Italian guerrilla campaign continued until 1943. This was followed by British recognition of full sovereignty, (i.e. without any special British privileges), with the signing of the Anglo-Ethiopian Agreement in December 1944. On 26 August 1942 Haile Selassie I issued a proclamation outlawing slavery. Ethiopia had between two and four million slaves in early 20th century out of a total population of about eleven million.
In 1952 Haile Selassie orchestrated the federation with Eritrea which he dissolved in 1962. This annexation sparked the Eritrean War of Independence. Although Haile Selassie was seen as a national hero, opinion within Ethiopia turned against him owing to the worldwide oil crisis of 1973, food shortages, uncertainty regarding the succession, border wars, and discontent in the middle class created through modernization.
He played a leading role in the formation of the Organisation of African Unity (OAU) in 1963.
Haile Selassie's reign came to an end in 1974, when a Soviet-backed Marxist-Leninist military junta, the "Derg" led by Mengistu Haile Mariam, deposed him, and established a one-party communist state which was called People's Democratic Republic of Ethiopia.