Austria (, ; Österreich ), officially the Republic of Austria (Republik Österreich, ), is a country in Central Europe comprising 9 federated states. Its capital, largest city and one of nine states is Vienna. Austria has an area of 83879 km2, a population of nearly 9 million people and a nominal GDP of $477 billion. It is bordered by the Czech Republic and Germany to the north, Hungary and Slovakia to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the west. The terrain is highly mountainous, lying within the Alps; only 32% of the country is below 500 m, and its highest point is 3798 m. The majority of the population speaks local Bavarian dialects as their native language, and German in its standard form is the country's official language. Other regional languages are Hungarian, Burgenland Croatian, and Slovene.
Austria played a central role in European History from the late 18th to the early 20th century. It initially emerged as a margraviate around 976 and developed into a duchy and later archduchy. In the 16th century, Austria started serving as the heart of the Habsburg Monarchy and the junior branch of the House of Habsburg – one of the most influential royal houses in history. As archduchy, it was a major component and administrative centre of the Holy Roman Empire. Following the Holy Roman Empire's dissolution, Austria founded its own empire in the 19th century, which became a great power and the leading force of the German Confederation. Subsequent to the Austro-Prussian War and the establishment of a union with Hungary, the Austro-Hungarian Empire was created. Austria was involved in both world wars; it started the first one under Emperor Franz Joseph and served as the birthplace of Adolf Hitler, who provoked the second one.
Hungary (Magyarország ) is a country in Central Europe. Spanning 93,030 km2 in the Carpathian Basin, it borders Slovakia to the north, Ukraine to the northeast, Austria to the northwest, Romania to the east, Serbia to the south, Croatia to the southwest, and Slovenia to the west. With about 10 million inhabitants, Hungary is a medium-sized member state of the European Union. The official language is Hungarian, which is the most widely spoken Uralic language in the world. Hungary's capital and its largest city and metropolis is Budapest. Other major urban areas include Debrecen, Szeged, Miskolc, Pécs and Győr.
The territory of modern Hungary was for centuries inhabited by a succession of peoples, including Celts, Romans, Germanic tribes, Huns, West Slavs and the Avars. The foundations of the Hungarian state were established in the late ninth century AD by the Hungarian grand prince Árpád following the conquest of the Carpathian Basin. His great-grandson Stephen I ascended the throne in 1000, converting his realm to a Christian kingdom. By the 12th century, Hungary became a regional power, reaching its cultural and political height in the 15th century. Following the Battle of Mohács in 1526, Hungary was partially occupied by the Ottoman Empire (1541–1699). It came under Habsburg rule at the turn of the 18th century, and later joined Austria to form the Austro–Hungarian Empire, a major European power.
Montenegro ( / Crna Gora ) is a country in Southeastern Europe on the Adriatic Sea. It borders Bosnia and Herzegovina to the northwest; Serbia and Kosovo to the east, Albania to the south and Croatia to the southwest. Montenegro has an area of 13,812 square kilometres and a population of 620,079 (2011 census). Its capital Podgorica is one of the twenty-three municipalities in the country. Cetinje is designated as the Old Royal Capital.
During the Early Medieval period, three principalities were located on the territory of modern-day Montenegro: Duklja, roughly corresponding to the southern half; Travunia, the west; and Rascia proper, the north. In 1042, archon Stefan Vojislav led a revolt that resulted in the independence of Duklja from the Byzantine Empire and the establishment of the Vojislavljević dynasty. The independent Principality of Zeta emerged in the 14th and 15th centuries, ruled by the House of Balšić between 1356 and 1421, and by the House of Crnojević between 1431 and 1498, when the name Montenegro started being used for the country. After falling under Ottoman rule, Montenegro regained de facto independence in 1697 under the rule of the House of Petrović-Njegoš, first under the theocratic rule of prince-bishops, before being transformed into a secular principality in 1852. Montenegro's de jure independence was recognised by the Great Powers at the Congress of Berlin in 1878, following the Montenegrin–Ottoman War. In 1905, the country became a kingdom. After World War I, it became part of Yugoslavia. Following the breakup of Yugoslavia, the republics of Serbia and Montenegro together established a federation known as the Federal Republic of Yugoslavia, which was renamed State Union of Serbia and Montenegro in 2003. On the basis of an independence referendum held in May 2006, Montenegro declared independence and the federation peacefully dissolved on 3 June of that year.
Romania (România ) is a country located at the crossroads of Central, Eastern, and Southeastern Europe. It borders the Black Sea to the southeast, Bulgaria to the south, Ukraine to the north, Hungary to the west, Serbia to the southwest, and Moldova to the east. It has a predominantly temperate-continental climate. With a total area of 238,397 square kilometres (92,046 sq mi), Romania is the 12th largest country and also the 7th most populous member state of the European Union, having almost 20 million inhabitants. Its capital and largest city is Bucharest, and other major urban areas include Cluj-Napoca, Timișoara, Iași, Constanța, Craiova, and Brașov.
The River Danube, Europe's second-longest river, rises in Germany's Black Forest and flows in a general southeast direction for 2857 km, coursing through ten countries before emptying into Romania's Danube Delta. The Carpathian Mountains, which cross Romania from the north to the southwest, include Moldoveanu Peak, at an altitude of 2544 m.
Serbia (Србија / Srbija ), officially the Republic of Serbia (Република Србија / Republika Srbija ), is a country situated at the crossroads of Central and Southeast Europe in the southern Pannonian Plain and the central Balkans. The sovereign state borders Hungary to the north, Romania to the northeast, Bulgaria to the southeast, North Macedonia to the south, Croatia and Bosnia and Herzegovina to the west, and Montenegro to the southwest. The country claims a border with Albania through the disputed territory of Kosovo. Serbia's population is about seven million. Its capital, Belgrade, ranks among the oldest and largest citiеs in southeastern Europe.
Slovakia ( Slovensko ), officially the Slovak Republic (Slovenská republika, ), 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 west, and the Czech Republic to the northwest. Slovakia's territory spans about 49000 km2 and is mostly mountainous. The population is over 5.4 million and consists mostly of Slovaks. The capital and largest city is Bratislava, and the second largest city is Košice. The official language is Slovak.
The Slavs arrived in the territory of present-day Slovakia in the 5th and 6th centuries. In the 7th century, they played a significant role in the creation of Samo's Empire and in the 9th century 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 would become the Kingdom of Hungary in 1000. In 1241 and 1242, much of the territory was destroyed by the Mongols during their invasion of Central and Eastern Europe. The area was recovered largely thanks to Béla IV of Hungary who also settled Germans which became an important ethnic group in the area, especially in what are today parts of central and eastern Slovakia. After World War I and the dissolution of the Austro-Hungarian Empire, the Czechoslovak National Council established Czechoslovakia (1918–1939). A separate (First) Slovak Republic (1939–1945) existed during World War II as a totalitarian, clero-fascist one-party client state of Nazi Germany. At the end of World War II, Czechoslovakia was re-established as an independent country. A coup in 1948 ushered in a totalitarian one-party state under the Communist regime during whose rule the country existed as a satellite of the Soviet Union. Attempts for liberalization of communism in Czechoslovakia culminated in the Prague Spring, which was crushed by the Warsaw Pact invasion of Czechoslovakia in August 1968. In 1989, the Velvet Revolution ended the Communist rule in Czechoslovakia peacefully. Slovakia became an independent state on 1 January 1993 after the peaceful dissolution of Czechoslovakia, sometimes known as the Velvet Divorce.
Ukraine (Україна; ), sometimes called the Ukraine, is a country in Eastern Europe. Excluding Crimea, Ukraine has a population of about 42.5 million, making it the 32nd most populous country in the world. Its capital and largest city is Kiev. Ukrainian is the official language and its alphabet is Cyrillic. The dominant religions in the country are Eastern Orthodoxy and Greek Catholicism. Ukraine is currently in a territorial dispute with Russia over the Crimean Peninsula, which Russia annexed in 2014. Including Crimea, Ukraine has an area of 603628 km², making it the largest country entirely within Europe and the 46th largest country in the world.
The territory of modern Ukraine has been inhabited since 32,000 BC. During the Middle Ages, the area was a key centre of East Slavic culture, with the powerful state of Kievan Rus' forming the basis of Ukrainian identity. Following its fragmentation in the 13th century, the territory was contested, ruled and divided by a variety of powers, including Lithuania, Poland, Austria-Hungary, the Ottoman Empire and Russia. A Cossack republic emerged and prospered during the 17th and 18th centuries, but its territory was eventually split between Poland and the Russian Empire, and finally merged fully into the Russian-dominated Soviet Union in the late 1940s as the Ukrainian Soviet Socialist Republic. In 1991 Ukraine gained its independence from the Soviet Union in the aftermath of its dissolution at the end of the Cold War. Before its independence, Ukraine was typically referred to in English as "The Ukraine", but most sources have since moved to drop "the" from the name of Ukraine in all uses.