Austria, formally the Republic of Austria, is a landlocked country in Central Europe, lying in the Eastern Alps. It is a federation of nine states, of which the capital Vienna is the most populous city and state. Austria is bordered by Germany to the northwest, the Czech Republic to the north, Slovakia to the northeast, Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the west. The country occupies an area of 83,879 km (32,386 sq mi) and has a population of around 9 million.
The area of today's Austria has been inhabited since at least the Paleolithic period. Around 400 BC, it was inhabited by the Celts and then annexed by the Romans in the late 1st century BC. Christianization in the region began in the 4th and 5th centuries, during the late Roman period, followed by the arrival of numerous Germanic tribes during the Migration Period.
