Quʿaiti sultanate, former semi-independent state in the southern Arabian Peninsula, in what is now Yemen. It was one of the largest sultanates in the British-ruled Aden Protectorate, the forerunner of independent southern Yemen; its capital was the port of Al-Mukallā. Its territory encompassed a stretch of the Gulf of Aden coast and much of the Ḥaḍramawt, an inland region extending northward to the Rubʿ al-Khali, the southern Arabian Desert. The sultanate was founded when the powerful Quʿaiti tribe arose early in the 19th century, challenging the dominant Kathiri sultanate. The two fought for supremacy in the Ḥaḍramawt until British pressure forced them to make peace in 1918. Both sultanates became part of South Yemen in 1967 (and the unified Yemen in 1990). The economy is based on agriculture, stock raising, tanning, weaving, and other industries.