Rabih az-Zubayr ibn Fadl Allah or Rabih Fadlallah (), usually known as Rabah in French (c. 1842 – April 22, 1900), was a Sudanese warlord and slave trader who established a powerful empire east of Lake Chad, in today's Chad. Born around 1842 to an Arabic tribe in Halfaya Al-Muluk, a suburb of Khartoum, he first served with the irregular Egyptian cavalry in the Ethiopian campaign, during which he was wounded. When Rabih left the army in 1860s, he became the principal lieutenant of the Sudanese slaveholder Sebehr Rahma. Lieutenant of al-Zubayr (1870–1879) In the 19th century, Khartoum had become a very important Arab slave market, supplied through companies of Khartumi established in the region of Bahr el Ghazal, where they resided in zarības (), thornbush-fortified bases kept by bāzinqirs (firearm-equipped slave soldiers). The warlord and slaveholder al-Zubayr Rahma Mansur assumed control of the region's zaribas, and was nominated in 1872 pasha and governor of Bahr el Ghazal for the khedive Isma'il, ruler of Egypt. Rabih, who was possibly a relative of al-Zubayr, was the chief lieutenant of the pasha. In 1874, al-Zubayr conquered the Sultanate of Darfur. In 1876, he went to Cairo to request the khedive to officially sanction his position in Darfur, but was instead imprisoned. This caused in 1878 the revolt of al-Zubayr's son, Suleyman, and of his lieutenants, like Rabih. In reaction the governor-general of Sudan, Charles George Gordon, made Romolo Gessi governor of Bahr el Ghazal, and sent him to suppress the rebellion; Suleyman surrendered July 15, 1879, and was executed. Rabih instead is said to have left Suleyman the day before he surrendered, but Gessi reports instead that he had retreated already in June, after having suffered heavy losses. Warlord (1879–1890) To escape from Egypt, Rabih left the Bahr el Ghazal, heading south with 700–800 bazingiris and 400 rifles. Using the tactics of the Khartumi, in the 1880s he carved out a kingdom between the basins of the Nile and the Ubangi, in the country of Kreich and Dar Benda, south of Ouaddai, a region he utterly devastated. In 1885, he attempted to return in Sudan following the invitation of the Mahdi Muhammad Ahmad, who had taken Khartoum from Egypt. The Mahdi had sent as ambassadors Zin el-Abeddin and Jabar, and Rabih followed them back to Darfur, proposing to meet the Mahdi at Omdurman; but when he learned of a plot to kill