Slovakia (Slovak: Slovensko) is a landlocked republic in Central Europe with a population of over five million. It is a member of the European Union (since May 1, 2004) and borders Czech Republic and Austria in the west, Poland in the north, Ukraine in the east and Hungary in the south. The largest city is its capital, Bratislava.------------From around 450 BC, the territory of modern-day Slovakia was settled by Celts, who built powerful oppida in Bratislava and Liptov. Silver coins with the names of Celtic kings represent the first known use of writing in Slovakia. From 6 AD, the expanding Roman Empire established and maintained a chain of outposts around the Danube. The Kingdom of Vannius, a barbarian kingdom founded by the Germanic tribe of Quadi, existed in western and central Slovakia from 20 to 50 AD.-----------In 1918, Slovakia joined the regions of Bohemia and neighbouring Moravia to form Czechoslovakia. During the chaos following the breakup of Austria-Hungary, Slovakia was in 1919 attacked by the provisional Hungarian Soviet Republic and 1/3 area of Slovakia temporarily became the Slovak Soviet Republic. During the Interwar period, democratic and prosperous Czechoslovakia was permanently threatened by revisionist governments of Germany and Hungary, until it was finally broken up by the Munich Agreement of 1938, when Slovakia became a separate state with a Nazi Germany sympathizing government (in lead with president Jozef Tiso). However, the anti-Nazi resistance movement launched a fierce armed insurrection, known as the Slovak National Uprising, in 1944. After World War II, Czechoslovakia was reassembled and came under the influence of the Soviet Union and its Warsaw Pact from 1945 onward. In 1969, the state became a federation of the Czech Socialist Republic and the Slovak Socialist Republic.-----------------The end of communist rule in Czechoslovakia in 1989, during the peaceful Velvet Revolution, was followed once again by the country's dissolution, this time into two successor states. Slovakia and the Czech Republic went their separate ways after January 1, 1993, an event sometimes called the Velvet Divorce, but Slovakia has remained close partners with the Czech Republic, as well as with other Central European countries within the Visegrad Group. Slovakia became a member of the European Union in May 2004.