Lisbon Treaty comes into force
The Lisbon Treaty, signed in 2007, came into force on December 1, 2009, after ratification by all EU member states. It marked a significant development in the European Union's constitutional framework, enhancing its governance and integration processes. Named after the city of Lisbon, the treaty addressed various institutional challenges, strengthen the role of the European Parliament, and aimed to make the EU more democratic and efficient. It was a milestone in the evolution of the EU, with Portugal playing a crucial role in its inception and title.