abundance of water. 627 CE: Muhammad orders the Third Raid on Banu Thalabah in Al-Taraf, now part of the Al-Ahsa governorate. 899: Al-Ahsa comes under control of the Qarmatian leader, Abu-Sa'id Jannabi, and is declared independent from the Abbasids of Baghdad. The capital is Al-Mu'miniya (near modern Hofuf). 1000: Al-Ahsa is among the 10 largest cities on earth, with 110,000 inhabitants. 1077: The Qarmatian state of Al-Ahsa is overthrown by the Uyunids. 1238: Usfurid dynasty takes over the region of Al-Ahsa and Al-Qatif. 1383: Usfurids are overthrown by the Jarwanids. 1440: The Jabrids take over Al-Ahsa, Qatif, Bahrain, and Kish Island, and extend their influence to eastern Nejd. 1521: Jabrid kingdom falls to the Muntafiq tribe of southern Iraq, who rule Al-Ahsa on behalf of the Ottoman Empire. The Ottomans station their garrisons in the region. 1670: the Ottomans are expelled by the tribe of Banu Khalid, who make their capital in Al-Mubarraz. 1795: Conquered by Saudi troops during the formation of the First Saudi State. 1818: Reconquered by the Ottoman Empire by Ottoman Egyptian forces overthrowing the First Saudi State in the process and granting the local tribe of Banu Khalid self-rule. 1830: Comes under the control of the Second Saudi State. 1871: The Second Saudi Dynasty loses the region to the Ottoman Empire again; however, this time it is directly ruled from Baghdad instead of by tribe of Bani Khalid under self-rule has had been the case in the past during Ottoman ownerships. 1913: King Abdulaziz Al Saud conquers Al-Ahsa Oasis, annexing it into his Kingdom of Najd. (This is recognised in the Treaty of Sèvres signed in 1920 with the other official partitionings of the Ottoman Empire.) 1932: Al-Ahsa becomes part of the Kingdom of Saudi Arabia, under the King Abdulaziz. 1930s: Huge petroleum deposits are discovered near Dammam, resulting in rapid modernization for the region. Early 1960s: The oil fields in Al-Ahsa reach the production level of 1 million barrels per day. Population and economy According to 2005 estimate, Al-Ahsa has over 908,000 people. All local residents are Muslim, including both Shia and Sunnis. Over the centuries, residents of the oasis have included the Banu Abdul Qays, the Banu Uqayl, and the Bani Khalid. Oil production and agriculture are the two main economic activities of the Al-Ahsa. Al-Ahsa is the home of some of the richest oil fields in the world. Natural fresh-water springs have surfaced