The most decisive evidence of change in the economic life of northern India after the Muslim expansion is numismatic. The Chandra dynasty coins are important in suggesting a prototype for the broad-struck silver and gold issues of the Delhi and Bengal sultanates. The metrology of the new coinage is firmly Indian with no parallels in earlier Islamic coinage. The remonetarization of the economy might have occurred by the middle of the thirteenth century, for at this period the Suhrawardi shaykhs of Multan left assets of lakhs of tankas. In the monetary system of the Delhi sultanate a firm equation between gold and silver appears to have been established at 1:10. The existence of smaller moneys of account in the Delhi is demonstrated by Baranl's numerous references to dings and dirams. It is clear that the establishment of a trimetallic coinage in northern India in the thirteenth century was heavily dependent on the remittance of gold and silver from Bengal.