Romania, one of the most populous countries of eastern Europe, has a rich and complex history. Its culture has evolved over centuries and is a product of many conquering tribes and empires whose civilizations eventually blended together. Since the overthrow of Nicolae Ceausescu and the communist system in 1989, Romania has struggled to restructure its political, economic, and social institutions into free and democratic establishments. Although communism and the Ceausescu dictatorship can be held accountable for many of Romania's current challenges, its complicated history has also had a lasting influence. The current government was elected in 2004, with Traian Basecu as president. The head of government is Prime Minister Popescu Tariceanu. Parliament is elected by popular vote for a four-year mandate; the prime minister is appointed by the president and approved by the Parliament.