High Quality Content by WIKIPEDIA articles! Constitution of Belgium dates back to 1831. Since then Belgium has been a parliamentary monarchy that applies the principles of ministerial responsibility for the government policy and the Trias Politica. The Constitution established Belgium as a centralised unitary state. However, since 1970, through successive state reforms, Belgium has gradually evolved into a federal state. The last radical change of the constitution was carried out in 1993 after which it was published in a renewed version in the Belgian Official Journal. One of the most important changes was the introduction of the Court of Arbitration whose competencies were expanded by a special law of 2003, to include Title II (Articles 8 to 32), and the Articles 170, 172 and 191 of the Constitution. The Court therefore developed into a constitutional court and in May 2007 it was formally redesignated Constitutional Court. This court has the authority to examine whether a law ora decree is in compliance with Title II and Articles 170, 172 and 191.