 His courtier Fakhr-e Mudabbir composed "Adab al-harb wa-l-shaja'a", a book on the art of warfare.Iltutmish implemented the "iqta" system of administrative grants in the Delhi Sultanate.This system, borrowed from the earlier Islamic dynasties of the Middle East, involved dedicating the revenues from a certain region to a subordinate in exchange for military service and political loyalty.