Al-Mansur Yahya (died 976) was an imam of the Zaidi state in Yemen, whose tenure as imam is counted from 934 to 976. Yahya bin Ahmad was the fifth son of the imam an-Nasir Ahmad, and the grandson of the founder-imam al-Hadi ila'l-Haqq Yahya. Even before the death of an-Nasir in 934, three of his sons quarreled bitterly among themselves. Although the Zaidi imamship was not strictly hereditary but depended on personal qualifications and descent from Muhammad, succession tended to take place within particular families descended from al-Qasim ar-Rassi (d. 860) and his grandson al-Hadi ila'l-Haqq Yahya (d. 911). Two sons of an-Nasir, al-Muntakhab al-Hasan (d. 936) and al-Mukhtar al-Qasim (d. 956), contested the dignity. None of them is recognized as a right imam in later Zaidi chronicles. Their