This chapter focuses on money markets and exchange rates in preindustrial Europe. The foreign exchange market was mostly based on bills of exchange, the instrument used to transfer money, and provide credit between distant centers in preindustrial Europe. In this chapter, first I explain bill of exchange operations, money market integration, usury regulations and circumventions to hide the market interest rate, as well as the evolution of bills of exchange in history, focusing mainly on the most relevant features generalized during the first half of the seventeenth century: endorsement and the joint liability rule, which facilitated the full expansion of the foreign exchange market beyond personal networks. Then, I describe the European geography of money in the mid eighteenth century, characterized by a very high degree of multilateralism with the triangle of Amsterdam, London, and Paris as the backbone of the European settlement system. Finally, I measure the cost of capital and relate it to liquidity. I show evidence of interest rates in the eighteenth century for Amsterdam, London, Paris, and Cadiz. While Amsterdam, London, and Paris presented low and similar interest rates, Cadiz had higher interest rates, mostly being double the cost of capital. These results seem to show a high inverse correlation between liquidity and interest rates, suggesting that the share in international trade of European centers might have been a powerful driver of international monetary leadership. While more empirical evidence and further research are needed, this approach opens the scope of the analysis beyond the national institutional explanation.