The Czech Republic (Česká republika ), also known by its short-form name, Czechia (Česko ), is a landlocked country in Central Europe bordered by Austria to the south, Germany to the west, Poland to the northeast and Slovakia to the southeast. The Czech Republic has hilly landscape that covers an area of with a mostly temperate continental climate and oceanic climate. It is a unitary parliamentary republic, with million inhabitants. Its capital and largest city is Prague, with 1.3 million residents; other major cities are Brno, Ostrava, Olomouc and Pilsen. The Czech state was formed in the late 9th century as the Duchy of Bohemia under the Great Moravian Empire. In 1002, the duchy was formally recognized as an Imperial State of the Holy Roman Empire, and became the Kingdom of Bohemia in 1198, reaching its greatest territorial extent in the 14th century. Prague was the imperial seat in periods between the 14th and 17th century. The Bohemian Reformation of the 15th century led to the Hussite Wars, which resulted in a period of confessional pluralism and relative religious tolerance. Following the Battle of Mohács in 1526, the whole Crown of Bohemia was gradually integrated into the Habsburg Monarchy. The Protestant Bohemian Revolt (1618–20) against the Catholic Habsburgs led to the Thirty Years' War. After the Battle of the White Mountain, the Habsburgs consolidated their rule, reimposed Catholicism, and adopted a policy of gradual Germanization. With the dissolution of the Holy Roman Empire in 1806, the Bohemian Crown lands became part of the Austrian Empire, and the Czech (Bohemian) language and literature experienced a cultural revival. In the 19th century, the Czech lands became heavily industrialized and were subsequently the core of the First Czechoslovak Republic, which was formed in 1918 following the collapse of the Austro-Hungarian Empire after World War I. Czechoslovakia was the only democracy in Central Europe during the interwar period. However, beginning in 1938, Nazi Germany systematically annexed the Czech Lands, while Slovakia became a German puppet state. The country was restored in 1945. Most members of the German-speaking minority were expelled following the war. The Communist Party of Czechoslovakia won a plurality in the 1946 elections and after the 1948 coup d'état established a one-party communist state under Soviet influence. Increasing dissatisfaction with the regime culminated in 1968 to the reform movement known as the Prague Spring, which ended in a Soviet-led invasion. Czechoslovakia remained occupied until the 1989 Velvet Revolution, which peacefully ended communist rule and reestablished democracy with a market economy. On 1 January 1993, Czechoslovakia peacefully dissolved, with its constituent states becoming the independent states of the Czech Republic and Slovakia. The Czech Republic joined NATO in 1999 and the European Union in 2004. It is also a member of the OECD, the United Nations, the OSCE, and the Council of Europe. The Czech Republic is a developed country with an advanced, high income social market economy. It is a welfare state with a European social model, universal health care, and tuition-free university education. It ranks 13th in the UN inequality-adjusted human development and 14th in the World Bank Human Capital Index ahead of countries such as the United States, the United Kingdom and France. It ranks as the eleventh safest and most peaceful country and performs well in democratic governance.