 They held power over Sanhadja Berber-descended zawiya (religious) and znaga (servant) tribes, extracting from these the horma tax in exchange for armed protection.Occasionally, such as in the case of the important Reguibat tribe, Zawāyā Berber groups would rise to Hassane status by growing in power and prestige and taking up armed raiding; they would then often Arabize culturally to fit the prevailing image of Hassane tribes as "original" Arabs.A good example of a Hassane tribe is the Río de Oro-centered Oulad Delim, which is considered as among the purest descendants of the Beni Hassan.