Central bank

A central bank, reserve bank, or monetary authority is an institution that manages a state's currency, money supply, and interest rates. Central banks also usually oversee the commercial banking system of their respective countries. In contrast to a commercial bank, a central bank possesses a monopoly on increasing the monetary base in the state, and usually also prints the national currency, which usually serves as the state's legal tender.

The primary function of a central bank is to control the nation's money supply (monetary policy), through active duties such as managing interest rates, setting the reserve requirement, and acting as a lender of last resort to the banking sector during times of bank insolvency or financial crisis. Central banks usually also have supervisory powers, intended to prevent bank runs and to reduce the risk that commercial banks and other financial institutions engage in reckless or fraudulent behavior. Central banks in most developed nations are institutionally designed to be independent from political interference. Still, limited control by the executive and legislative bodies usually exists.

Prior to the 17th century most money was commodity money, typically gold or silver. However, promises to pay were widely circulated and accepted as value at least five hundred years earlier in both Europe and Asia. The Song dynasty was the first to issue generally circulating paper currency, while the Yuan Dynasty was the first to use notes as the predominant circulating medium. In 1455, in an effort to control inflation, the succeeding Ming Dynasty ended the use of paper money and closed much of Chinese trade. The medieval European Knights Templar ran an early prototype of a central banking system, as their promises to pay were widely respected, and many regard their activities as having laid the basis for the modern banking system.

...
Wikipedia