Aug 18, 1955 to Mar 27, 1972
Southern SudanThe First Sudanese Civil War (also known as the Anyanya Rebellion or Anyanya I, after the name of the rebels, a term in the Madi language which means 'snake venom'), was a conflict from 1955 to 1972 between the northern part of Sudan and the southern Sudan region that demanded representation and more regional autonomy. Half a million people died over the 17 years of war, which may be divided into three stages: initial guerrilla war, Anyanya, and South Sudan Liberation Movement.
The government was unable to take advantage of rebel weaknesses because of their own factionalism and instability. The first independent government of Sudan, led by Prime Minister Ismail al-Azhari, was quickly replaced by a stalemated coalition of various conservative forces, which was in turn overthrown in the coup d'état of Chief of Staff Lt. Gen. Ibrahim Abboud in 1958.
In 1969, Gordon Muortat Mayen was elected unanimously as the new leader of the South. Southern Sudan in this time changed their name to the Nile Republic and resumed warfare against Khartoum, however some of the former leader Jaden's troops would not accept a Dinka leader and fought against the Anyanya.
In 1971, former army lieutenant Joseph Lagu formed a successful coup d'état against Gordon Muortat with help from Israel, which pledged him their support. He then gathered all the guerilla bands under his Southern Sudan Liberation Movement (SSLM).
In-fighting between Marxist and non-Marxist factions in the ruling military class led to another coup in July 1971 and a short-lived administration by the Sudanese Communist Party before anti-Communist factions put Nimeiry back in control of the country.
Mediation between the World Council of Churches (WCC) and the All Africa Conference of Churches (AACC), both of which spent years building up trust with the two combatants, eventually led to the Addis Ababa Agreement of March 1972 ending the conflict.