Founded in Oman in 1741 by Imam Ahmad ibn Said of the Ibadi imams after expelling the Persians. Ruler was imam, formally elected by ulama. Continues to rule through the present, although the title of imam is no longer used and rulers are no longer elected. Religious prestige is based on ties to the Ibadi tradition. Established a trade-based empire encompassing East Africa and the Indian Ocean region. Ruled Zanzibar until 1964. Current ruler is Sultan Qabus ibn Said, who has modernized the political regime and crushed political and religious opposition.