Abū l-Ḥasan ʿAlī l-Hādī b. Muḥammad b. ʿAlī b. Mūsā al-ʿAskarī (d. 254/868) was the tenth Imām of the Imāmī Shīʿīs. Known also as al-Naqī (the pure one) or Abū l-Ḥasan al-Thālith (the third), he was born in Ṣurayyā, a village three miles from Medina founded by his great-grandfather, the seventh Imām of the Imāmiyya, Mūsā l-Kāẓim. The sources give birthdates ranging from Dhū l-Ḥijja 212/March 828 to Rajab-Dhū l-Ḥijja 214/September-February 830. His mother is