Slovakia (/sloʊˈvækiə, -ˈvɑːk-/ ; Slovak: Slovensko [ˈslɔʋenskɔ] ), officially the Slovak Republic (Slovak: Slovenská republika [ˈslɔʋenskaː ˈrepublika] ), is a landlocked country in Central Europe. It is bordered by Poland to the north, Ukraine to the east, Hungary to the south, Austria to the southwest, and the Czech Republic to the northwest. Slovakia's mostly mountainous territory spans about 49,000 square kilometres (19,000 sq mi), with a population of over 5.4 million. The capital and largest city is Bratislava, while the second largest city is Košice. The Slavs arrived in the territory of present-day Slovakia in the fifth and sixth centuries. In the seventh century, they played a significant role in the creation of Samo's Empire. In the ninth century, they established the Principality of Nitra, which was later conquered by the Principality of Moravia to establish Great Moravia. In the 10th century, after the dissolution of Great Moravia, the territory was integrated into the Principality of Hungary, which then became the Kingdom of Hungary in 1000. In 1241 and 1242, after the Mongol invasion of Europe, much of the territory was destroyed. The area was recovered largely thanks to Béla IV of Hungary, who also settled Germans, leading them to become an important ethnic group in the area, especially in what are today parts of central and eastern Slovakia. (Source: Wikipedia.org, CC BY-SA)