Originally called the Reform Treaty, the Lisbon Treaty amended the previous two treaties which were instrumental in the creation of the European Union. After its ratification the two treaties that it amended were renamed; the Maastricht Treaty became the Treaty on European Union (TEU) and the the Rome Treaty was called the Treaty establishing the European Community (TEC). The Lisbon Treaty was signed by the EU member states in 2007, and finally put into action on 1 December, 2009 after several modifications.
The primary aim of this treaty was to promote greater efficiency and coherence of the European Union as an entity. It achieved this by increasing the power of the European parliament, requiring a lower voting majority - from unanimous to double majority- in Council of Ministers voting, and creating unification in EU legal protocols. The Lisbon Treaty additionally made a provision for a European Council president and a High Representative of the Union for Foreign Affairs and Security Policy. It also made the Charter of Fundamental Rights a legally binding constitution.
Critics of the Lisbon treaty feared that it would concentrate too much power in a centralized European Union and threaten the sovereignty of the individual member nations.