The common European currency, the euro has existed since 1999; however, its introduction
followed after decades of monetary integration and legal, economic and financial preparation.
The first ten years of the monetary union were successful. The second decade was dominated
by managing the crisis that was first global in character but then became limited
to the crisis of the currency zone. In the initial phase, ad hoc type crisis management
measures were taken; later, more systematic protection measures and institutional
developments followed. Nevertheless, it is the resistance of the currency zone to
future crises that has been established rather than its sustainability-the latter
is yet to be ensured.