Abu'l-Futuh al-Hasan ibn Ja'far was the Sharif of Mecca for the Fatimid Caliphate from 994 until 1039. He was also briefly proclaimed as an anti-Caliph in a rebellion against the Fatimid Caliphate in Palestine in 1012/3.
In July 1012, at the instigation of Abu'l-Qasim al-Husayn ibn Ali al-Maghribi, he was briefly acclaimed as anti-Caliph with the title of al-Rashid bi-llah ("Righteous with God") during the Jarrahid-led Bedouin revolt against the Fatimid rule in Palestine. He raised a considerable sum of money and joined the rebels in their capital of Ramla, where he was initially warmly received and acclaimed as "Commander of the Faithful". Soon, however, the money he had brought with him ran out and the Jarrahids ceased to respect him, while they were willing to receive gifts and money from the Fatimid Caliph, al-Hakim bi-Amr Allah. Disheartened, Hasan returned to Mecca and Fatimid allegiance, while the Jarrahid rebellion was crushed by the Fatimid troops in late summer 1013.