The euro was released on 1 January 1999, following a decade of preparations: for the first three years, it was a 'invisible' currency, used exclusively for accounting purposes and electronic payments. Coins and banknotes were introduced on 1 January 2002, and the largest currency transition in history occurred in 12 EU countries.
The yen was first produced in 1869, following the Meiji Restoration, and was officially accepted as the basic unit in 1871 as part of the monetary reform. That year, the government prohibited the exchange of clan notes, paper money manufactured and circulated by feudal lords since the late 16th century.