The civil war and its consequences have led to the deaths of between 180,000 and 300,000 people, while the United Nations estimates that 2.4 million have been forced from their homes with a further 200,000 refugees fleeing to Chad.
The rebellion in Darfur is being fought mainly by the Sudan Liberation Movement (SLM) and the Justice and Equality Movement (JEM).
The rebel groups are demanding more autonomy and economic development for the black African-populated region which they see as "marginalised" by Arab Khartoum and have demanded a more equitable distribution of the nation's resources, especially oil.
The rebel forces are fighting Sudanese government troops, supported by Arab militias who are accused of serial atrocities in the region, including massacres, rapes and the destruction of homes.
On March 31 2005, the UN approved a resolution which allowed those responsible for such atrocities to be tried by the International Court of Justice, after long debates linked to the United States' opposition to this court.
The Darfur conflict has no basis in religion with its entirely Muslim and Arabic speaking population of Arab and African tribes, unlike the 21-year civil war of southern Sudan with its majority animist and Christian population.
The population comprises both peasant farmers and nomadic peoples spread over three Sudanese states, West, North and South Darfur, which cover a total of 500,000 sq km (200,000 square miles).
The region is mainly one of high plateaus with volcanic summits culminating in the 3,071 metres (10,134 feet) of the highest peak in the Jebel Marra mountains.
There is considerable mineral wealth in the region including oil, uranium and copper while cattle raising is one of the main sources of income.
The region has been, for a number of years an area of conflict between the nomadic and agricultural tribes with raids by armed groups. However there was no armed political movement in the region until February 2003, when a Darfur Liberation Front emerged, splitting into the SLM and JEM.
The JEM is said to have up to 7,000 men while the armed branch of the SLM has 16,000 fighters. The rebels claim to control all the rural areas while the Sudanese army remains confined, they say, to the main cities in the region.
In February 2004 the SLM joined the ranks of the National Democratic Alliance (NDA), a coalition which groups part of the northern opposition to Khartoum and the southern rebels.