The term lender of last resort originates from the French expression dernier ressort. While the concept itself had been used previously, the term, "lender of last resort", was supposedly first used in its current context by Sir Francis Baring in his Observations on the Establishment of the Bank of England which was published in 1797. In 1763 the king was the lender of last resort in Prussia. Different definitions of the lender of last resort exist in the literature. A comprehensive one is the following: "the discretionary provision of liquidity to a financial institution (or the market as a whole) by the central bank in reaction to an adverse shock which causes an abnormal increase in demand for liquidity which cannot be met from an alternative source". This means that the central bank is the lender (provider of liquidity) of last resort (if there is no other way to increase the supply of liquidity when there is a lack thereof). The function has been performed by many central banks since the beginning of the 20th century. The goal is to prevent financial panics and bank runs spreading from one bank to the next due to a lack of liquidity.