History of the European Union since 2004 the decision on 31 March 2010 to abolish the Western European Union. In 2007, the fifth enlargement completed with the accession of Romania and Bulgaria on 1 January. 53 MEPs joined the Parliament along with two commissioners, for which two new posts were created in the Commission. The post created for the Romanian Commissioner was Multilingualism, which was criticised by some for its narrow scope. Negotiating process with Croatia as an official candidate country had been stalled for 10 months due to Slovenia's blockade of Croatia's EU accession, which was lifted in September 2009 after an agreement. Croatia has since
European Union Slovenia joined the Union. In 2007, Bulgaria and Romania became EU members. The same year, Slovenia adopted the euro, followed in 2008 by Cyprus and Malta, by Slovakia in 2009, by Estonia in 2011, by Latvia in 2014, and by Lithuania in 2015. On 1 December 2009, the Lisbon Treaty entered into force and reformed many aspects of the EU. In particular, it changed the legal structure of the European Union, merging the EU three pillars system into a single legal entity provisioned with a legal personality, created a permanent President of the European Council, the first of which was