History of Forex. 2

Originally, coins were simply minted from the preferred metal, but in stable political regimes the introduction of a paper form of governmental IOUs (I owe you) gained acceptance during the Middle Ages. Such IOUs, often introduced more successfully through force than persuasion were the basis of modern currencies.
Before World War I, most central banks supported their currencies with convertibility to gold. Although paper money could always be exchanged for gold, in reality this did not occur often, fostering the sometimes disastrous notion that there was not necessarily a need for full cover in the central reserves of the government