Which treaty established the European Central Bank's legal foundation in 1992?

The Maastricht Treaty established the legal foundation for the European Central Bank in 1992. Formally called the Treaty on European Union, it was signed in Maastricht, the Netherlands, on February 7, 1992.

The treaty created the European Union and set a timetable for economic and monetary union. It also established the convergence criteria that member states were expected to meet before adopting the euro and entering the single monetary system.

The European Central Bank itself began operations in 1998, ahead of the euro's launch as an accounting currency in 1999. The Treaty of Rome, signed in 1957, created the European Economic Community but did not establish the ECB.