Abu Sa'id al-Jannabi

Abu Sa'id Hasan ibn Bahram al-Jannabi (Arabic: أبو سعيد حسن بن بهرام الجنابي, romanized: Abū Saʿīd Ḥasan ibn Bahrām al-Jannābī; 845/855–913/914) was a Persian and the founder of the Qarmatian state in Bahrayn (an area comprising the eastern parts of modern Saudi Arabia as well as the Persian Gulf). By 899, his followers controlled large parts of the region, and in 900, he scored a major victory over an Abbasid army sent to subdue him. He captured the local capital, Hajar, in 903, and extended his rule south and east into Oman. He was assassinated in 913, and succeeded by his eldest son Sa'id.

His religious teachings and political activities are somewhat unclear, as they are reported by later and usually hostile sources, but he seems to have shared the millennialist Isma'ili belief about the imminent return of the mahdī, hostility to conventional Islamic rites and rituals, and to have based the Qarmatian society on the principles of communal ownership and egalitarianism, with a system of production and distribution overseen by appointed agents. The Qarmatian "republic" he founded would last until the late 11th century.