A country of southwest Asia at the southern tip of the Arabian peninsula. It was ruled by various peoples, such as the Sabaeans, Himyarites, Romans, Ethiopians, and Persians, in ancient times. It was conquered in the 7th century AD by Muslim Arabs and became part of the Ottoman Empire in the 16th century. The northern part (known as Yemen or North Yemen) was established as an independent kingdom in 1918 and made a republic in 1962. The southern part consisted of several British protectorates in the late 1800s and early 1900s. Britain withdrew from the area in 1967, and South Yemen became independent soon after. The two united in May 1990. San'a is the capital and the largest city.