A treatise on the finance of the Muslim world, by the thirteenth century mathematician and astronomer: Persian text with critical notes, translation, and extensive commentary. This pamphlet, addressed to a Universal Ruler (presumably a Mongol Khan) explains control of the men of the sword, the army and of the men of the pen; lists the revenues of rulers. including all kinds of taxes (both traditional and modern), war booty, and treaure trove; the expenditures of the king on personnel, aid to the poor, and the messenger system; and the immunity of the property of orphans, the absent, and charitable foundations. The commentary relates this (especially Tusi's insistence on the righteous ways of former kings) to Muslim economic history, explains the types of taxes, and etymologizes and defines technical terms.