Nonetheless, the dissident group retained the name Qarmaṭī. Their greatest stronghold remained in Bahrain, which at this period included much of eastern Arabia as well as the islands that comprise the present state. It was under Abbasid control at the end of the ninth century, but the Zanj Rebellion in Basra disrupted the power of Baghdad. The Qarmaṭians seized their opportunity under their leader, Abu Sa'id al-Jannabi, who captured Bahrain’s capital Hajr and al-Hasa in 899, which he made the capital of his state and once in control of the state he sought to set up a utopian society.