 As such it was a fundamental feature of Mamluk society, on the one hand giving way to a military hierarchy that crystallized into an even more developed economic hierarchy and that had substantial economic interests in society at large; on the other hand, it deeply characterized the realm's economic and social development, its agriculture, grain trade, and rural demography in particular.The system largely consisted of land assignments from the state in return for military services.Land was assessed by the periodic "rawk" (cadastral survey), which consisted of a survey of land parcels (measured by "feddan" units), assessment of land quality and the annual estimated tax revenue of the parcels, and classification of a parcel's legal status as "waqf" (trust) or "iqtaʿ".