This introductory chapter describes salient features of the Bank of Amsterdam and proposes that these were sufficiently advanced to qualify the Bank as a modern central bank. Sophisticated central banking, however, was not the Bank’s original mission, which instead was to apply contemporaneous information technology (double-entry accounting) within a limited-purpose institution to facilitate the movement of safe assets (trade coins) through Amsterdam. By the eighteenth century, the Bank had moved well beyond its original design and evolved into a de facto fusion of two banks, active and passive, linked by a common liability — fiat ledger money. This chapter outlines this evolution, which is explored in greater detail in subsequent chapters.