The horma was a tribute paid by subservient tribes to their protectors in traditional Sahrawi people, Sahrawi-Moorish society in today's Mauritania and Western Sahara in North Africa. The powerful Hassane warrior tribes would extract it from low-caste Znaga tribes, where each member was forced to personally pay an overlord in the dominant tribe. The forms and rates of horma varied throughout the region and through history, and was normally dependent on the relations of strength between the tribes involved. It could be paid in cattle, goods or services.

* Hodges, Tony (1983), ''Western Sahara: The Roots of a Desert War'', Lawrence Hill Books () * Mercer, John (1976), ''Spanish Sahara'', George Allen & Unwid Ltd () *Pazzanita, Anthony G. and Hodge, Tony (1994), ''Historical Dictionary of Western Sahara'', Scarecrow Press () * Thompson, Virginia and Adloff, Richard (1980), ''The Western Saharans. Background to Conflict'', Barnes & Noble Books () Society of the Sahrawi Arab Democratic Republic Society of Mauritania Arab culture Berbers in Mauritania Berbers in Western Sahara {{ethno-stub

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