AHOM, the branch of the Tai race settled in and giving its name to Assam (q.v.). This people came into Assam in the 13th century under a leader named Sukupha and gradually extended their rule westward down the Brahmaputra valley, which they dominated till its invasion by the Burmese early in the 19th cen tury. They instituted and retained in Assam a form of govern ment in which taxes were paid by personal service and the popu lation was organized in paiks of three householders, one of whom had always to be on duty. Religion was animistic until Hinduized; society was organized in clans (khel), originally exogamous, but tending to become under Hinduism endogamous occupational groups. There was a written language in script derived ultimately from Devanagari, but now, like the spoken tongue, extinct, though palm-leaf books written in it are still extant. (See also SHAN.) See Hastings' Encyclopaedia of Religion and Ethics (s.v.) "Ahom"; E. A. Gait, History of Assam (1926) .