Qarmatians

The Qarmatians were an Isma'ili Shia militant movement led by an Arabized dynasty of Persian descent. Claiming an Alid descent, the Qarmatians were centred in al-Ahsa in Eastern Arabia, where they established a religious state in 899 CE. The Qarmatians adhered to a syncretic branch of Sevener Ismaili Shia Islam, and were ruled by a dynasty founded by Abu Sa'id al-Jannabi. They rejected the claim of the Fatimid caliph Abdallah al-Mahdi Billah to the imamate and, clinging to their belief in the coming of the Mahdi, revolted against both the Fatimid and Abbasid caliphates. The Qarmatians are perhaps most notable for sacking Mecca in 930 CE under the leadership of Abu Tahir al-Jannabi. This violent act outraged the contemporary Muslim world, particularly because of their theft of the Black Stone and the desecration of the Zamzam Well with the corpses of pilgrims during the Hajj season.