During the 3d millennium B.C., Bahrain (known in Sumerian as Dilmun) was already an important trade center, functioning as a transshipment point between Arabia and India. In the ancient world it was also famous for the pearling conducted in the waters surrounding the islands. The Greeks knew the island as Tylos. The term Bahrain was used to describe the entire Persian Gulf coast of Arabia in the early Islamic era; the island was also known as Awal or Aval. Bahrain was ruled in the 16th cent. by Portugal and intermittently from 1602 to 1783 by Persia. The Persians were expelled by an Arabian family that established the present ruling dynasty, the al-Khalifas. In 1861, Bahrain became a British protectorate.
Nearly a century later, demonstrations and strikes in the 1950s and 60s demanded greater popular participation in government. Iran claimed the islands in 1970 after the United Nations reported that the inhabitants desired independence. In 1971, after Britain withdrew from the Persian Gulf area, Bahrain became independent. In 1973 a constitution that limited the sheikh's powers was adopted and an elected national assembly established, but in 1975 the sheikh suspended the constitution and dissolved the national assembly. Bahrain was a founding member of the Gulf Cooperation Council (GCC) in 1981, along with neighboring Persian Gulf countries, and it is also a member of the Arab League.
In the 1980s and 1990s relations with Qatar were strained by a dispute over the Hawar Islands and the large natural-gas resources of the Dome field (in the shallow sea between both countries). In the late 1980s a causeway was built connecting Bahrain and Saudi Arabia. After the end of the Iran-Iraq War (1988), attempts were made to improve relations with Iran; persistent irritants to Iran were the poverty among Bahrain's Shiite majority and the small Shiite representation in Bahrain's cabinet. During the 1991 Persian Gulf War, coalition forces were allowed extensive use of Bahraini territory. In 1993 a consultative council (Shura) was appointed to replace the long-dissolved national assembly. In the mid and late 1990s unrest among Bahrain's Shiites has led to opposition protests and violence; the restoration of an elected parliament was one of the main demands. In 1996 more than 50 people were arrested for involvement in what was said to be an Iranian-backed coup attempt.
Sheikh Isa bin Salman al-Khalifa, who had ruled since 1961, died in 1999; he was succeeded by his son, Sheikh Hamad bin Isa al-Khalifa. The new ruler moved gradually toward increased democracy for Bahrain. In 2000 he called for the establishment of a national committee to write a new national charter. The charter, which established a constitutional monarchy, was approved in Feb., 2001; the same month a general amnesty for political prisoners and exiles was declared.
Bahrain was proclaimed a kingdom in 2002, and the Shura was dissolved prior to the assembly elections. Because King Hamad had established an appointed upper house in the national parliament, which had not been part of the charter approved in 2001, a number of groups (including the largest Shiite association) called for an electoral boycott; turnout in the October elections was 53%. The elected deputies were largely moderate Sunnites and independents. The election marked the first time that women in a Arab Persian Gulf monarchy could vote or run for national office. Shiite-Sunni tensions in Bahrain increased again after the U.S. invasion of Iraq.
In Sept., 2006, a former government adviser of Sunni Sudanese descent accused a number of government officials (but not the king or prime minister) of conspiring to manipulate elections and use other means to maintain Sunni control of Bahrain's government and society. The detailed report was denounced by the head of Bahrain intelligence service, who was accused of being central to the conspiracy, and the adviser was deported and then accused of attempting to overthrow the government and other crimes. An investigation into the evidence and charges was sought by Shiite opposition groups. In the Nov.–Dec., 2006, parliamentary elections themselves, the Shiite opposition secured 18 seats while Sunnis won 22; conservatives and Islamists were dominant in both groups.
In 2009 tensions between the government and Shiite opposition activists led to arrests of activist leaders and recurring protests against the government; the protests continued into 2010, with an increased security crackdown in the second half of the year. The results of the Oct., 2010, parliamentary elections were largely similar to those in 2006 except that Sunni Islamists won fewer seats; the opposition again failed to secure a majority.
In Feb.–Mar., 2011, there were massive antigovernment protests in the capital, paralleling the protests in other Arab nations; opposition Shiite legislators resigned after protesters were killed in February (and the main Shiite party boycotted the by-elections held in September). In March, Saudi and Emirati forces entered Bahrain at the request of the government, and Bahrain, which painted the initially relatively nonsectarian protests as an Iranian-inspired Shiite attempt at revolution, quickly and violently quashed the protests and arrested hundreds. A number of opposition leaders and others were convicted and harshly sentenced.
In the aftermath of the protests, sectarian tensions in Bahrain increased, aggravated by anti-Shiite repression that was economic and social as well as political. An indepdendent government report (Nov., 2011) on the events of February and March said that security forces had used excessive force and engaged in torture; the report also said it could not find a clear link between the demonstrators and Iran. Some constitutional reforms were adopted in the first half of 2012, but the opposition criticized them as inadequate. The situation subsequently remained tense and unsettled, and the government continued to take repressive measures against the opposition.