Abu Hashim al-Hasan
Abu Hashim al-Hasan (died 1040) was an imam of the Zaidi state in Yemen who ruled part of the Yemeni highland in 1031–1040. Abu Hashim al-Hasan was a fifth-generation descendant of al-Qasim al-Rassi (d. 860), the theological portal figure of Zaydiyyah Islam. In 1031, the year after the violent death of the former imam al-Mu’id li-Din Illah, he claimed the imamate. He was able to seize San'a. One of the local grandees, Ibn Abi Hashid, fled, while another one, Nunsur bin Abi'l-Futuh, submitted. Abu Hashim's authority in  San'a lasted until 1037, when he was expelled by the tribesmen of Hamdan. The Hamdanites later invited Ja'far, brother of the old imam al-Mahdi al-Husayn, to rule the city as emir. The following years were filled with contests over San'a, and Abu Hashim was able to regain control over the commercially important place for a brief term. After he had lost the city for good, he withdrew to Sa'dah in the north, which was the old stronghold of the Zaydiyyah. The hard pressed Abu Hashim died in 1040. A new pretender, Abu'l-Fath an-Nasir ad-Dailami, arrived  from Persia, possibly before Abu Hashim's death. Having proclaimed his da'wa (call for the imamate), he proceeded to seize Sa'dah and San'a some years later, in 1046.