Abu Hashim al-Hasan (died 1040) was an imam of the Zaidi state in Yemen who ruled part of the Yemeni highlands between 1031 and 1040.
Abu Hashim al-Hasan was a fifth-generation descendant of al-Qasim al-Rassi (d. 860), one of the founders of the theological traditions of the Zaydi branch of Shi'a Islam.
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 city for a brief term.
[4] Having proclaimed his da'wa (call for the imamate), he proceeded to seize Sa'dah and San'a some years later, in 1046.