The discovery of a circulating medium enormously facilitated the progress of commerce, and it was not long before a class of people grew up who specialized in this particular form of business and became financiers and moneylenders. Bankers and financiers were known in Rome and Athens, and we know that some machinery existed by which the monetary claims of one country on another could be settled by something that fulfilled the functions of the modern bill of exchange. The actual provision of metallic currency has from the earliest times been almost entirely under the control of the government which took into its own hands, as an essential part of the police protection which it gives to the people, the coining of currency, stamping the coin in such a way that anybody who took one might know that he was getting a certain weight of a precious metal. But the money-dealing business very soon developed the machinery of credit by which anybody who had an enterprise or a venture out of which he expected to make an attractive profit could, if he had sufficient property to pledge, provide himself with the means to finance it between the day that he started on his operations and the day when he brought home his profits: and this business also became international, though not, perhaps, as rapidly as commerce had overstepped the boundaries between one people and another. In the _Merchant of Venice_ we find Antonio trading with all the countries of the then known world, From Tripolis, from Mexico, and England, From Lisbon, Barbary, and India, but we do not find that Shylock was lending money on at all the same international scale. When communication was slow, difficult, and untrustworthy, money-lending at a distance was made very risky, because it was impossible for the lender to keep the watchful eye on the borrower's operations and credit that is required if he is to feel comfortable in his venture. For a Lombard Street banker to lend money to a merchant in Cheapside payable at a year hence was, until comparatively lately, a much safer enterprise than to lend it to a merchant in Paris, because the local borrower was always under the lender's observation. If he were overtrading or living on too lavish a scale it would at once be noticed and reported. Nevertheless, international finance made steady progress through somewhat obscure beginnings. We know that Philip II of Spain was heavily indebted to moneylenders all over the Continent, and that by his famous repudiation he carried consternation throughout Europe.[28] Edward III was also heavily indebted to Florentine bankers, and he also omitted to pay his debt; and it is said that the descendants of the Florentine bankers still have a claim against the English Crown in consequence[29]; but it was not until after the creation of stock exchanges and the machinery of a public market in securities that international finance became a question of general importance.