The Federal Republic of Germany is a member state of the United Nations, NATO, the G8 and the G4 nations, and is a founding member of the European Union. It has the largest population and largest economy of all European Union member states. Germany is both the world's third largest economy and its largest exporter of goods. Germany is facing major demographic change. Its fertility rate of 1.39 children per mother is one of the lowest in the world, and the federal statistics office estimates the population will shrink to approximately 75 million by 2050. Chemnitz is thought to be the city with the lowest birth rate in the world.
Budapest's recorded history begins with the Roman town of Aquincum, founded around AD 89 on the site of an earlier Celtic settlement near what was to become Óbuda, and from 106 until the end of the 4th century the capital of the province of lower Pannonia. The Hungarians led by Árpád settled in the territory at the end of the 9th century, and a century later officially founded the Kingdom of Hungary. Research places the probable residence of the Árpáds an early place of central power near what became Budapest. The Tatar invasion in the 13th century quickly proved that defence is difficult on a plain. King Béla IV of Hungary therefore ordered the construction of reinforced stone walls around the towns and set his own royal palace on the top of the protecting hills of Buda. In 1361 it became the capital of Hungary.