Ethiopian Civil War
In March 1975, revolutionaries abolished the monarchy.
The Crown Prince Asfaw Wossen settled permanently in New York City, where several other members of the Imperial family lived.
The other members who were still in Ethiopia at the time of the revolution were imprisoned.
The imprisoned members of the Imperial family included Prince Wossen's father, Emperor Haile Selassie, his daughter by his first marriage, Princess Ijigayehu, his sister, Princess Tenagnework, and many of his nephews, nieces, relatives and in-laws.
In 1975 his father, Emperor Haile Selassie, died in detention. In 1977 his daughter, Princess Ijigayehu, died in detention. Members of the Imperial family remained imprisoned until 1988 (for the women) and 1989 (for the men).
The Derg eliminated its political opponents between 1975-77 in response to the declaration and instigation of an Ethiopian Red Terror against the Derg by various opposition groups, primarily the Ethiopian People's Revolutionary Party (EPRP).
Like the Derg, it was Marxist. Brutal tactics were used by both sides, including executions, assassinations, torture and the imprisonment of tens of thousands without trial, most of whom were innocent.
The Ethiopian Red Terror was the "urban guerrilla" chapter of the brutal war.
The government battled guerrillas fighting for Eritrean independence for its entire period in power, as well as with other rebel groups ranging from the conservative and pro-monarchy Ethiopian Democratic Union (EDU) to the far leftist EPRP.
The Tigrayan People's Liberation Front (TPLF), which would become the eventual victor in this conflict, was one of the smaller groups at this time and the Derg did not bother to mount a serious campaign against them until the Semien Zemecha in 1978.
During the revolution the Derg fulfilled its main slogan of "Land to the Tiller" by redistributing land that once belonged to landlords to the peasant tilling the land.
Mismanagement, corruption and general hostility to the Derg's violent rule was coupled with the draining effects of constant warfare and the separatist guerrilla movements in Eritrea and Tigray, resulting in a drastic decline in general productivity of food and cash crops.
Although Ethiopia is prone to chronic droughts, no one was prepared for the scale of drought and famine that struck the country in the mid-1980s, in which 400,000-590,000 people are estimated to have died.
Hundreds of thousands fled the economic misery, conscription and political repression, and went to live in neighboring countries and all over the Western world, creating an Ethiopian diaspora for the first time.
Insurrections against Derg rule sprang up particularly in the northern regions of Tigray and Eritrea.
Hundreds of thousands were killed as a result of the Red Terror, forced deportations or from the use of hunger as a weapon under Mengistu's rule.
The Derg continued its attempts to end the rebellions with military force.
They initiated several campaigns against both internal rebels and the Eritrean People's Liberation Front, the most important ones being Operation Shiraro, Operation Lash, Operation Red Star and Operation Adwa, which led to its decisive defeat in the Battle of Shire on 15-19 February 1989.
In 1991, the Mengistu government was finally toppled by its own officials and a coalition of rebel forces, the Ethiopian People's Revolutionary Democratic Front (EPRDF), after their bid for a push on the capital Addis Ababa became successful.
There was some fear that Mengistu would fight to the bitter end for the capital, but after diplomatic intervention by the United States, he fled to asylum in Zimbabwe, where he still resides.
The EPRDF immediately disbanded the Workers' Party of Ethiopia (the political arm of the Derg) and arrested almost all of the prominent Derg officials shortly afterwards.
In December 2006, 72 officials of the Derg were found guilty of genocide. Thirty-four people were in court, 14 others died during the lengthy process and 25, including Mengistu, were tried in absentia.