Khartoum is the capital city of Sudan, located in the east of the country at the confluence of the White Nile and the Blue Nile, the two major tributaries of the Nile river. The city was founded in 1821 by Ibrahim Pasha, following the incorporation of Sudan into Egyptian rule. It was the site of the Siege of Khartoum on 13 March 1884, when the Egyptian-held city fell to Mahdist forces.