Aquick glance at the monetary history of Europe and the Muslim world from 1000 to 1500 shows that in monetary matters the two halves of the Mediterranean followed very different courses. Whereas Europe minted virtually no gold until the middle of the thirteenth century, 2 but greatly increased its supplies of silver coins, the Islamic countries through much of this same period were experiencing an acute silver famine during which they were able to mint only gold, billon, and base metals. Then a remarkable reversal occurred. Towards the end of the twelfth century, silver reappeared in abundance in the Arab world and soon displaced gold as the basis of many currencies. A little later, Europe began minting gold coins in large quantities and her silver currencies began to falter. The dissimilarity seems total. The one side of the Mediterranean mirrored in reverse what was happening on the other shore.