A new front of Marxist-Leninist revolution erupted in Africa, with revolutions in Benin, Congo-Brazzaville, and Somalia ; Marxist-Leninist liberation fronts in Angola and Mozambique revolting against Portguese colonial rule ; the overthrow of Haile Selassie and the creation of the Derg communist military junta in Ethiopia ; blacks led by Robert Mugabe in Rhodesia revolting against white-minority rule there.

As part of their sweeping changes, the Derg ordered Addis Ababa University temporarily closed March 4, 1975 and dispatched its 50, 000 students to the countryside to help build support for the new regime.

However, General Aman Andom quarreled with the radical elements in the Derg over the issue of a new military offensive in Eritrea and the proposal to execute the high officials of the Emperor's former government.

Brigadier General Tafari Benti became both the new Chairman of the Derg and head of state, with Mengistu and Atnafu Abate as his two vice-Chairmen with the new ranks of Lieutenant-Colonels.

In 1987 the Derg was formally dissolved and the country became the People's Democratic Republic of Ethiopia ( PDRE ) under a new constitution.

Although the Derg government officially came to an end 22 February 1987, three weeks after a referendum approved the constitution for the PDRE, it was not until that September the new government was fully in place and the Derg formally abolished.

The surviving members of the Derg, however, remained in power as the leaders of the new civilian regime.

However, a committee of low ranking officers called the Derg, who had been empowered to investigate corruption in the military, arrested Tsehafi Taezaz Aklilu and most of the men who had served in his cabinet, as well as the new Prime Minister and his cabinet.

This new committee became what was to be known as the Derg.

After the takeover by the Derg junta, TNO claimed that armed struggle was necessarily to remove the new regime.

Its creation led to the dissolution of the Derg, the military dictatorship formerly in charge of the country, and established a Communist one-party state with the WPE as supreme authority, though several ex-Derg officials retained posts in the new government.

But because the Patriarch had named these new bishops without the permission of the new Derg communist junta, all five men were arrested, and the Patriarch was eventually executed.

* 1991 – The capital city of Addis Ababa, falls to the Ethiopian People's Revolutionary Democratic Front, ending both the Derg regime in Ethiopia and the Ethiopian Civil War.

In December 2009, a 96-page report titled Human Rights in Ethiopia: Through the Eyes of the Oromo Diaspora, compiled by the Advocates for Human Rights, documented human rights violations against the Oromo in Ethiopia under three successive regimes: the Abyssinian Empire under Haile Selassie, the Marxist Derg and the current Ethiopian government of the Ethiopian People ’ s Revolutionary Democratic Front ( EPRDF ), dominated by members of the Tigray People ’ s Liberation Front ( TPLF ) and which was accused to have arrested approximately 20, 000 suspected OLF members, to have driven most OLF leadership into exile, and to have effectively neutralized the OLF as a political force in Ethiopia.

Mengistu Haile Mariam (, pronounced ; born 21 May 1937 ) is an Ethiopian politician who was the most prominent officer of the Derg, the Communist military junta that governed Ethiopia from 1974 to 1987, and President of the People's Democratic Republic of Ethiopia from 1987 to 1991.

However there is no doubt that the Derg under Mengistu's leadership ordered the deaths without trial of 61 ex-officials of the Imperial government on 23 November 1974, and later of numerous other former nobles and officials including the Patriarch of the Ethiopian Orthodox Church, Abuna Theophilos, in 1977.

From 1977 through 1978, resistance against the Derg ensued, led primarily by the Ethiopian People's Revolutionary Party ( EPRP ).

In May 1991, the Ethiopian People's Revolutionary Democratic Front ( EPRDF ) forces advanced on Addis Ababa from all sides, and Mengistu fled the country with 50 family and Derg members.

Following the arrest and imprisonment of Abune Tewophilos, Patriarch of Ethiopia, by the Marxist Derg regime that had deposed Emperor Haile Selassie in 1974, Pope Shenouda III refused to recognise the cleric who was installed as the Ethiopian Patriarch's successor.

Four years later, the pro-American Ethiopian Emperor Haile Selassie was overthrown in a 1974 coup by the Derg, a radical group of Ethiopian army officers led by the pro-Soviet Mengistu Haile Mariam, who built up relations with the Cubans and Soviets.

Formed from the union of the TPLF and the Ethiopian Peoples Democratic Movement ( EPDM ) in early 1989, they were later joined by the OPDO ( Oromo of the TPLF and EPLF, and Oromo members of EPDM ) and the Ethiopian Democratic Officers ’ Revolutionary Movement ( a small body of Derg officers captured by TPLF, most notably at Shire in February 1989, which was later disbanded after the establishment of the Transitional Government of Ethiopia.

Lacking western ties, the Mulu Wongel church was outlawed by the Derg Ethiopian government in 1972.

However, over the following months radicals in the Ethiopian military came to believe he was acting on behalf of the hated aristocracy, and when a group of notables petitioned for the release of a number of government ministers and officials who were under arrest for corruption and other crimes, three days later the Derg was announced.

The Derg, which originally consisted of soldiers at the capital, broadened its membership by including representatives from the 40 units of the Ethiopian Army, Air Force, Navy, Kebur Zabagna ( Imperial Guard ), Territorial Army and Police: each unit was expected to send three representatives, who were supposed to be privates, NCOs and junior officers up to the rank of major.

The reign of the Derg in Ethiopia is remembered as giving rise to the Ethiopian Civil War.

Once the Derg had gained victory over these groups and successfully fought off an invasion from Somalia in 1977, it engaged in a brutal war between the government and armed groups which included guerrillas fighting for Eritrean independence, rebels based in Tigray ( which included the nascent Tigrayan Peoples ' Liberation Front ), and other groups that ranged from the conservative and pro-monarchy Ethiopian Democratic Union to the far leftist Ethiopian People's Revolutionary Party.

In December, 2010, the Ethiopian government has commuted the death sentence of 23 Derg officials.

The Ethiopian government paroled almost all of those Derg officials that have been jailed for 20 years.

He was again proclaimed on the deposition of his father by the Derg on 12 September 1974, but he never accepted this proclamation as legitimate, and in any case this brief reign was ended with the abolition of the Ethiopian monarchy in March 1975.

When instead he announced to the Ethiopian Embassy in London that he would be moving to that city shortly, the Embassy asked the Derg for instructions as to whether it should receive him as King and head-of-state, or if it should receive him as Crown Prince upon his arrival in the United Kingdom.

The Berta, Gumuz and Shinasha tend to have more in common with the people of neighbouring Sudan than with other Ethiopian peoples, while the Amhara and Tigrayans, who are known as Habesha ( or " highlanders ") are recent arrivals, who began to settle in the region during the Derg era.

After the death of Abuna Takla Haymanot in 1988, Abune Merkorios who had close ties to the Derg ( Communist ) government was elected Patriarch of Ethiopia.

There were strikes and demonstrations in Addis Ababa in 1974 ; and in February of that year, Haile Selassie ’ s government was replaced by the Derg, a military junta led by Mengistu Hailemariam ; but the Council was still Amhara-dominated, with only 25 non-Amhara members out of 125.

The Derg government turned back the Somali invasion, and made deep strides against the Eritrean secessionists and the TPLF as well.

Before it became the government in 1991, the EPRDF was a rebel group battling the military junta known as the Derg.

'" Aman fought the majority of the Derg over three central issues: the size of the Derg, which he felt was too large and unwieldy ; the policy to be taken towards the Eritrean Liberation Front ( ELF ); and over the punishment of the numerous aristocrats and former government officials in the Derg's custody.

The Derg installed a government which was socialist in name and military in style.

This violence immediately claimed at least eight Derg members, plus numerous Derg supporters, and soon provoked a government counteraction-the Red Terror.

The Coordinating Committee of the Armed Forces, Police, and Territorial Army, or the Derg ( Ge ' ez " Committee "), was officially announced 28 June 1974 by a group of military officers to maintain law and order due to the powerlessness of the civilian government following widespread mutiny in the armed forces of Ethiopia earlier that year.

In July the Derg obtained key concessions from the Emperor, Haile Selassie, which included the power to arrest not only military officers, but government officials at every level.

In August, after a proposed constitution creating a constitutional monarchy was presented to the Emperor, the Derg began a program of dismantling the imperial government in order to forestall further developments in that direction.

After eliminating units loyal to him — the Engineers, the Imperial Bodyguard and the Air Force — the Derg removed General Aman from power and executed him along with some supporters and 60 officials of the previous Imperial government on November 24, 1974.

Many of the Derg members remained in key government posts, and remained as the members of the Central Committee and the Politburo of the Workers ' Party of Ethiopia ( WPE ), which became Ethiopia's civilian version of the Eastern bloc Communist parties.