amir reduced his garrisons in Bahrain and Zubarah in order to re-position his troops. Said bin Sultan of Muscat capitalized on this opportunity and attacked the Wahhabi garrisons in Bahrain and Zubarah. The fort in Zubarah was set ablaze and the Al Khalifa were effectively returned to power. British involvement Britain's desire for secure passage for East India Company ships led it to impose its own order in the Persian Gulf. An agreement known as the General Maritime Treaty was signed between the East India Company and the sheikhs of the coastal area (later to be known as the Trucial Coast) in 1820. It acknowledged British authority in the Persian Gulf and sought to end piracy and the slave trade. Bahrain became a party to the treaty, and it was assumed that Qatar, as a dependency, was also a party to it. A report compiled by Major Colebrook in 1820 gives the first descriptions of the major towns in Qatar. All of the coastal cities mentioned in his report were situated near the Persian Gulf pearl banks and had been practicing pearl fishing for millenniums. Until the late eighteenth century, all of the principal towns of Qatar including Al Huwaila, Fuwayrit, Al Bidda and Doha were situated on the east coast. Doha developed around the largest of these, Al Bidda. The population consisted of nomadic and settled Arabs and a significant proportion of slaves brought from East Africa. As punishment for piracy committed by the inhabitants of Doha, an East India Company vessel bombarded the town in 1821. They razed the town, forcing between 300 and 400 natives to flee. A survey carried out by the British in 1825 notes that Qatar did not have a central authority and was governed by local sheikhs. Doha was ruled by the Al-Buainain tribe. In 1828, a member of the Al-Buainain murdered a native of Bahrain, prompting the Bahraini sheikh to imprison the offender. The Al-Buainain tribe revolted, provoking the Al Khalifa to destroy their fort and expel them from Doha. The expulsion of the Al-Buainain granted the Al Khalifa more jurisdiction over Doha. Bahraini–Saudi contention Desiring to keep surveillance over the proceedings of the Wahhabi, Bahrain stationed a government official named Abdullah bin Ahmad Al-Khalifa on the coast of Qatar as early as 1833. Turning against the Bahrainis, he instigated the people of Al Huwailah to revolt against the Al Khalifa and