Among the Arab tribes of Oman the only acknowledged nobility is that reckoned by tribal ancestry (asl), affirmed by genealogies and oral history, and known by all. This goes not only for the Sultanate of Oman, but also for Omani tribes which have settled in East Africa. One is either a noble or a member of a group of inferior status, that is, the clients (mawâlî) who comprise the labour force in village communities. Slaves ('abid) by definition have no status. This society is thus socially divided between tribal organisations and client groups. On the other hand, within the tribe itself clans or sections appear to be equal or egalitarian, by law and in reality.