autonomy. During the 17th century the Funj state reached its widest extent, but in the following century it began to decline. A coup in 1718 brought a dynastic change, while another one in 1761–1762 resulted in the Hamaj regency, where the Hamaj (a people from the Ethiopian borderlands) effectively ruled while the Funj sultans were their mere puppets. Shortly afterwards the sultanate began to fragment; by the early 19th century it was essentially restricted to the Gezira. The coup of 1718 kicked off a policy of pursuing a more orthodox Islam, which in turn promoted the Arabisation of the state. In order to legitimise their rule over their Arab subjects the Funj began to propagate an Umayyad descend. North of the confluence of the Blue and White Niles, as far downstream as Al Dabbah, the Nubians adopted the tribal identity of the Arab Jaalin. Until the 19th century Arabic had succeeded in becoming the dominant language of central riverine Sudan and most of Kordofan. West of the Nile, in Darfur, the Islamic period saw at first the rise of the Tunjur kingdom, which replaced the old Daju kingdom in the 15th century and extended as far west as Wadai. The Tunjur people were probably Arabised Berbers and, their ruling elite at least, Muslims. In the 17th century the Tunjur were driven from power by the Fur Keira sultanate. The Keira state, nominally Muslim since the reign of Sulayman Solong (r. 1660–1680), was initially a small kingdom in northern Jebel Marra, but expanded west- and northwards in the early 18th century and eastwards under the rule of Muhammad Tayrab (r. 1751–1786), peaking in the conquest of Kordofan in 1785. The apogee of this empire, now roughly the size of present-day Nigeria, would last until 1821. Turkiyah and Mahdist Sudan (1821–1899) In 1821, the Ottoman ruler of Egypt, Muhammad Ali of Egypt, had invaded and conquered northern Sudan. Although technically the Vali of Egypt under the Ottoman Empire, Muhammad Ali styled himself as Khedive of a virtually independent Egypt. Seeking to add Sudan to his domains, he sent his third son Ismail (not to be confused with Ismaʻil Pasha mentioned later) to conquer the country, and subsequently incorporate it into Egypt. With the exception of the Shaiqiya and the Darfur sultanate in Kordofan, he was met without resistance. The Egyptian policy of conquest was expanded and intensified by Ibrahim Pasha's son, Ismaʻil,