Kathiri sultanate, former semi-independent state in the southern Arabian Peninsula, in the inland Hadhramaut region now included in Yemen. The sultanate, with its capital at Saywūn (Sayʾūn), once extended from the Wadi Ḥaḍramawt, an intermittent stream, northward to the Rubʿ al-Khali, the vast southern Arabian desert. The Kathīrī tribe dominated the Hadhramaut from about 1500 until the early 19th century, when the rising Quʿaiti sultanate challenged it. The British intervened on behalf of the latter, and the Kathīrī people were cut off from the seacoast under a treaty that was signed in 1918. The sultanate was incorporated into independent South Yemen in 1967. (North and South Yemen merged in 1990.) The principal occupations of the Kathīrī people are agriculture, stock raising, and handicrafts.