The franc is the name of several currency units, most notably the French franc, the currency of France until it aopted the euro in 1999 (by law, 2002 de facto); and the Swiss franc, still a major world currency today due to the prominence of Swiss financial institutions. The name is said to derive from the Latin inscription francorum rex ("King of the Franks") on early French coins, or from the French franc, meaning "free" (and "frank").