Al-Hadi Sharaf ad-Din (1820 – June 8, 1890) was a claimant for the Zaidi imamate of Yemen in the years 1878–1890, acting in opposition to the Ottoman occupiers of the country.
His period saw a tribal embryo of a state taking form in the highlands of Yemen, which would be strengthened by his successors as imams, and eventually usher into the expulsion of the Ottoman Turks in the early 20th century.
A concerted attack against the Turkish positions was launched in the summer of 1884, where al-Hadi Sharaf ad-Din strove to subjugate the well-watered regions to the north-west of San'a.
The German traveller Eduard Glaser who visited Yemen in 1884 summarized the situation at that time, and described al-Hadi Sharaf ad-Din as a leader of fanatics.
At the time of his visit the area controlled by the Turks was restricted to a line between Luhayyah and Hajjah, together with Amran, San'a, Dhamar, Rada, Qa'tabah and the land between Ta'izz and Mocha.
[8] In July in the same year the ulema appointed his brother-in-law Muhammad bin Yahya Hamid ad-Din as their new imam, continuing the anti-Turkish struggle.