A claimant Mahdi can wield great temporal, as well as spiritual, power: claimant Mahdis have founded states (e.g. the late 19th-century "Mahdiyah" in Sudan), as well as religions and sects (e.g. Bábism, or the Ahmadiyya movement). The continued relevance of the Mahdi doctrine in the Muslim world was most recently emphasised during the 1979 seizing of the Grand Mosque in Mecca, Saudi Arabia, by at least 200 militants led by Juhayman al-Otaibi, who had declared his brother-in-law, Muhammad bin abd Allah al-Qahtani, the Mahdi.