Answer
The Abbasid dynasty, to which Al-Hadi belonged, was a prominent Islamic caliphate that ruled from 750 to 1258 AD. Established by the descendants of Abbas ibn Abd al-Muttalib, the dynasty oversaw a golden age of Islamic civilization, characterized by significant advancements in science, literature, art, and architecture. Al-Hadi's reign as the fourth Abbasid caliph lasted from 785 to 786 AD, during which he faced various challenges and internal conflicts.