Rabih az-Zubayr ibn Fadl Allah or Rabih Fadlallah, usually known as Rabah in French, was a Sudanese warlord and slave trader who established a powerful empire east of Lake Chad, in today's Chad.

Muhammad Ahmad bin Abdullah bin Fahal was a Sudanese religious and political leader. In 1881, he claimed to be the Mahdi, and led a war against Ottoman-Egyptian rule in Sudan which culminated in a remarkable victory over the British in the Siege of Khartoum, while also slowing and defeating the British during their unsuccessful Nile Expedition to resupply the Khartoum Garrison. He created a vast Islamic state extending from the Red Sea to Central Africa, and founded a movement that remained influential in Sudan a century later.