A warm, shallow gulf between worlds
The Persian Gulf, called the Arabian Gulf by many Arabic speakers, is a shallow arm of the Arabian Sea. It runs about 1,000 kilometres northwest from the Strait of Hormuz to the delta of the Tigris and Euphrates. The water is warm and very salty, summer heat is intense, and there are many reefs, shoals and islands. The shallows were a source of one of the region’s most valuable products, pearls, while the position of the Gulf at the meeting point between Mesopotamia, Iran, Arabia and the Indian Ocean made it a natural route for trade.
Early voyages
Written records from Mesopotamia in the third millennium BC refer to trading partners called Dilmun, Magan and Meluhha. Dilmun is usually identified with Bahrain and nearby areas, Magan with the region of Oman and the Emirates, and Meluhha is often linked to the Indus Valley, although these identifications involve some uncertainty. Mesopotamian texts record the import of copper, stone, timber, and other goods, brought by Dilmun and Magan voyages in reed-and-bitumen and wooden boats. Archaeological finds, including Indus-style seals found in the Gulf and Mesopotamia, support the existence of this long-distance exchange. Copper in particular is a theme in the study of the Gulf copper trade.
Dhows, monsoon and the medieval Gulf
By the early centuries AD, and with greater certainty by the Islamic period, the Gulf was part of a wider Indian Ocean network. Basra, founded in the seventh century, and ports such as Siraf on the Iranian coast, active especially in the ninth and tenth centuries, handled trade in textiles, spices, pottery, timber and other goods. Arabic and Persian accounts from the period describe voyages to India and China, and archaeologists have found Chinese ceramics at Gulf sites. Ships of these routes were sailing vessels with lateen sails, many of them forerunners of the dhow, and they often relied on the monsoon trade winds of the Indian Ocean to make passages to India and East Africa. The knowledge of such voyages was passed down by pilots, and the Arab sea pilots such as Ibn Majid, who wrote in the fifteenth century, left detailed navigational texts.
Hormuz, an island city at the entrance to the Gulf, rose to prominence in the later Middle Ages as a toll-collecting entrepôt. The Portuguese took it in 1515 as part of their attempt to control Indian Ocean trade, and they held it until 1622, when a Persian force supported by English ships expelled them.
The pearl diving economy
Pearls from the Gulf were traded for many centuries, and from at least the nineteenth century the industry was a mainstay of coastal communities in Bahrain, Kuwait, Qatar and the Trucial coast. Pearling took place in the summer months, with boats leaving for the oyster beds for several weeks or months. A diver worked from a vessel, typically descending with a weight on a rope, using a nose clip and holding his breath, while a colleague, the hauler, pulled him up. Cut fingers, sharks, and diseases among the crews were common risks, and the work was hard.
The boats used were typically locally built wooden sailing vessels of the dhow family, with a captain and crews who were often bound to him by advances of money. Under the traditional system, divers and crew frequently began each season in debt to the captain, who himself depended on credit from merchants who bought the pearls. This credit system, and the heavy debts it could produce, is a recurring theme in studies of pearl diving fleets and is sometimes described as exploitative. Pearls from the Gulf were sold through merchants in Bahrain and Dubai to buyers in India, and then to Europe.
The pearl economy was at its height in the late nineteenth and early twentieth centuries, when hundreds of boats took part, though accurate numbers vary between sources. In the 1920s and 1930s, the development of cultured pearls in Japan reduced demand and prices for natural pearls, and the world depression of the same period added to the pressure. The industry collapsed in many places, causing hardship, just before the discovery of oil began to transform the region.
British treaties and the oil age
During the nineteenth century, Britain concluded a series of agreements with the rulers of the lower Gulf, beginning with the General Maritime Treaty of 1820, with the aim of suppressing what it termed piracy and protecting its own routes to India. The coast became known to the British as the Trucial Coast. Britain remained the dominant external power in the Gulf into the twentieth century and withdrew from its protective treaties in 1971.
The discovery of oil in Bahrain in the 1930s, and later in Kuwait, Saudi Arabia, Iran, Iraq and the Emirates, changed the Gulf’s maritime role. Oil tankers became the main large vessels, and the Strait of Hormuz became one of the most important shipping chokepoints in the world. Ports such as Dubai, Jebel Ali, Dammam and Bandar Abbas now handle container and bulk cargo, yet dhows continue to trade along parts of the coast, a link with the older maritime world.