United Arab Emirates, federation of seven independent states lying along the east-central coast of the Arabian Peninsula, formerly called the Trucial States (from the Perpetual Maritime Truce signed with Great Britain in 1853). The states, occupying a vaguely defined area formerly known as the Pirate Coast, as well as 80 km (50 mi) of coast on the Gulf of Oman, are bounded on the north by Qatar and the Persian Gulf, on the east by the Gulf of Oman, and on the south and west by Saudi Arabia. Area, 77,700 sq km (30,000 sq mi).

The population grew rapidly in the 1970s and 1980s, largely because of alien workers, and was estimated (1991) at 1,909,000. Population density was about 25 persons per sq km (about 64 per sq mi).
The states are Abu Dhabi (Abu Zaby), Ajman, Dubayy, al-Fujayrah, Ras al-Khaymah, ash-Shariqah, and Umm al-Qaywayn. The town of Abu Dhabi is the union capital (population, 1989 estimate, 363,432); the port of Dubayy (population, 1980, 265,702) is the commercial center of the union and northern Oman and has a large transshipment trade. The capitals of the states are on the Persian Gulf coast, except the capital of al-Fujayrah, which is on the coast of the Gulf of Oman. The hinterland is sandy and unproductive. Most of the inhabitants live in the coastal towns and the rest in inland oases. The traditional occupations are date tending, pearl diving, camel breeding, and fishing. The oil industry is now a major employer.
Most of the states granted oil exploration concessions, but only Abu Dhabi, Dubayy, and to a lesser extent ash-Shariqah, have found significant reserves. In the late 1980s the emirates produced about 526.4 million barrels of crude oil a year; the annual output of natural gas was 16.4 billion cu m (579 billion cu ft). Revenue from petroleum exports financed the construction of an aluminum smelter in Dubayy during the 1980s; an industrial complex was built at ar-Ruways, and facilities to transport and liquefy natural gas were also developed.
The non-oil-producing member states receive financial assistance from Abu Dhabi and other neighboring Arab countries. The emirates are members of the Organization of Petroleum Exporting Countries (OPEC). The unit of currency is the dirham, adopted in 1973 to replace the Qatar riyal and the Bahrain dinar previously used (3.67 dirham equal U.S.$1; 1994).
The former Trucial States, also known as Trucial Oman, were under the military protection of Great Britain from 1853 until December 2, 1971, when six of the states became independent as the United Arab Emirates. Ras al-Khaymah joined on February 11, 1972. Each of the seven states has its own hereditary ruler; together they comprise the highest body of the federal government, the Supreme Council of Rulers. It elects from its members a president and vice president. The United Arab Emirates were part of the United Nations-led, 28-nation allied forces that defeated Iraq in the Persian Gulf War in 1991.