Member States were expected to make further efforts so as to ensure a smooth transition to Stage Three. For example, they had to amend national laws so as to make them compatible with the Treaty and to make their NCBs fully independent before the start of Stage Three. In 1995, three new Member States - Austria, Finland and Sweden - joined the European Union.
Finally, on 1 January 1999, the European Union reached a new and unprecedented stage of economic integration. With the launch of the euro, 11 countries gave up their monetary sovereignty and transferred the task of conducting the single monetary policy to a supranational institution.