North Sudan is inhabited by Muslim Arabs, whilst the south is inhabited by black African Christians. The Arab Muslims saw themselves as slave masters, whilst they looked down on black Africans as slaves. The last period of war was triggered by President Gaafar Nimeiry deciding to modify the Addis Ababa Agreement, including imposing Islamic law throughout the country, without the consent of the south, which had been operating within Sudan but as a largely autonomous state.

The war lasted from 1983 to 2005 until the signing of the Nairobi Comprehensive Peace Agreement of that year which re-established southern Sudan's former autonomy together with a promise of a referendum on independence in 2011 which was duly held seeing South Sudan emerge as the world's newest independent nation in 2011.

Despite the peace accord there has been ongoing conflict and violence particularly in Darfur where a separate war rages until this day where the Sudan Liberation Army together with other groups have taken up arms against the government in an attempt to repel Muslim Arabs and seek recognition of the area as an equal and valued partner within Sudan.