Treaty of Lisbon

The Treaty of Lisbon is the latest treaty of the European Union. It took effect on 1 December 2009. The purpose of the new treaty was to simplify and clarify decision making in the Union. It complements earlier treaties.

The treaty changed the roles, duties and composition of the Union institutions to better respond to the needs of the wider Union. It answers the question:“Who does what in the EU and when?”

The Treaty of Lisbon also included important administrative and policy reforms. For example, the Charter of Fundamental Rights became a permanent part of the Treaty. It defines the European Union’s values, objectives and principles.