Locations
The treaties of the European Union outline the locations of the following institutions: The European Parliament has its seat in Strasbourg, hosting twelve monthly plenary sessions (including budget session). Brussels hosts additional sessions and committees (including being used in September 2008 for normal sittings when the Strasbourg chamber was damaged). Luxembourg hosts the Secretariat of the European Parliament. The Council of the European Union has its seat in Brussels, except during April, June, and October, when meetings are held in Luxembourg.
The European Commission also has its seat in Brussels, although some departments are hosted by Luxembourg. The European Court of Justice, the General Court, and the Court of Auditors are based in Luxembourg along with the European Investment Bank. The Economic and Social Committee and the Committee of the Regions are entirely based in Brussels while the European Central Bank is based in Frankfurt and Europol is the only agency to have its seat fixed by the treaties, in the Hague.
Separately, the Treaty of Nice establishes Brussels as the venue for all formal summits of the European Council after 2004. However some extraordinary sessions are sometimes held outside the city. The European Council's seat is however fixed by a declaration rather than a protocol, meaning it is less binding than the other seats.
The 2011 Treaty Establishing the European Stability Mechanism (ESM) states that the seat of the ESM must be in Luxembourg. The ESM should be ratified and active in mid-2013 and it is allowed to establish a liaison office in Brussels.
Read more about this topic: Location Of European Union Institutions