Sterling (ISO code: GBP) is the currency of the United Kingdom and nine of its associated territories. The pound (sign: £) is the main unit of sterling, and the word "pound" is also used to refer to the British currency generally, often qualified in international contexts as the British pound or the pound sterling. In British English, its most common nickname is "quid."
Sterling is the world's oldest currency that is still in use and that has been in continuous use since its inception. It is currently the fourth most-traded currency in the foreign exchange market, after the United States dollar, the euro, and the Japanese yen. Together with those three currencies and Renminbi, it forms the basket of currencies which calculate the value of IMF special drawing rights. As of late 2022, sterling is also the fourth most-held reserve currency in global reserves.
The Bank of England is the central bank for sterling, issuing its own banknotes, and regulating issuance of banknotes by private banks in Scotland and Northern Ireland. Sterling banknotes issued by other jurisdictions are not regulated by the Bank of England; their governments guarantee convertibility at par. Historically, sterling was also used to varying degrees by the colonies and territories of the British Empire.
"Sterling" is the name of the currency as a whole while "pound" and "penny" are the units of account. This is analogous to the distinction between "renminbi" and "yuan" when discussing the official currency of the People's Republic of China.
There are various theories regarding the origin of the word "sterling". The Oxford English Dictionary states that the "most plausible" etymology is a derivation from the Old English steorra for "star" with the added diminutive suffix "-ling", to yield "little star". The reference is to the silver penny used in Norman England in the twelfth century, which bore a small star.
Another argument, according to which the Hanseatic League was the origin of both its definition and manufacture as well as its name is that the German name for the Baltic is "Ostsee", or "East Sea", and from this the Baltic merchants were called "Osterlings", or "Easterlings".