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.