In or shortly before 1881 an ascetic religious leader, Mohammed Ahmed, living with his disciples on an island in the White Nile, is inspired by the revelation that he is the long-awaited Mahdi. Publicly announcing his new role, he calls for the creation of a strict Islamic state. The immediate result is an order from Khartoum for his arrest, followed by the escape to the mountains of the Mahdi and his followers.
The fervour of the faithful, combined with the Mahdi's own skills, results during 1883 in a series of astonishing victories - the rapid defeat of three Egyptian armies (the last of them under a British general) and the capture of several key towns, including El Obeid.
The Egyptian garrisons further to the south are now dangerously isolated. So is the capital, Khartoum, with its vulnerable population of non-Sudanese civilians. In this crisis the British government, led at the time by Gladstone, hastily appoints Gordon to rush south to Khartoum on a rescue mission. But he is provided with woefully inadequate support.