A federation of seven states on the southeast portion of the Arabian peninsula: Abu Dhabi, Ajman, Dubai, Fujairah, Ras al-Khaimah, Sharjah and Umm al-Qaiwain. In 1820 a treaty of peace was concluded between Great Britain and native rulers. During the 19th century the rulers agreed to suppression of the slave trade and restriction of foreign relations to Great Britain. The Trucial Council was established in 1952 and defense treaties with Great Britain terminated. In 1971 an independent six-member federation was formed, with Ras al-Khaimah joining the federation in 1972. (From Webster's New Geographical Dictionary, 1988, p1250).