The Triumph of the Sun (Courtney publication order #12) by Wilbur Smith

In the Sudan, decades of brutal misgovernment by the ruling Egyptian Khedive in Cairo precipitates a fierce and bloody rebellion and Holy War headed by a charismatic new religious leader, the Mahdi or 'Expected One'. The British are forced to intervene to protect their national interests and to attempt to rescue the hundreds of British subjects stranded in the country.

Along with hundreds of others, British trader and businessman Ryder Courtney is trapped in the capital city of Khartoum. It is here that he meets Captain Penrod Ballantyne of the 10th Hussars, as well as the British Consul, David Benbrook, and his three beautiful daughters. Against the vivid and bloody backdrop of the siege of Khartoum, in which British General Charles George Gordon is killed and the British retreat, these three powerful men fight to survive.