Persian attempts to reconquer the island in 1783 and in 1785 failed; the 1783 expedition was a joint Persian-Qawasim invasion force that never left Bushehr. The 1785 invasion fleet, composed of forces from Bushehr, Rig and Shiraz was called off after the death of the ruler of Shiraz, Ali Murad Khan. Due to internal difficulties, the Persians could not attempt another invasion. In 1799, Bahrain came under threat from the expansionist policies of Sayyid Sultan, the Sultan of Oman, when he invaded the island under the pretext that Bahrain did not pay taxes owed. The Bani Utbah solicited the aid of Bushire to expel the Omanis on the condition that Bahrain would become a tributary state of Persia. In 1800, Sayyid Sultan invaded Bahrain again in retaliation and deployed a garrison at Arad Fort, in Muharraq island and had appointed his twelve-year-old son Salim, as Governor of the island. The Bani Utbah laid siege to Arad Fort later that year, ejecting Salim from power. In 1802, Sayyid Sultan once again sailed with a fleet to Bahrain however, the Al Khalifa enlisted the aid of Wahhabis from the mainland which forced the Omanis to abort their invasion.