Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of 312,696 km2 (120,733 sq mi). Poland has a population of over 38 million, and is the fifth-most populous member state of the European Union. Warsaw is the nation's capital and largest metropolis, and other major cities include Kraków, Łódź, Wrocław, Poznań, Gdańsk, and Szczecin.
Poland's territory extends from the Baltic Sea in the north to the Sudeten and Carpathian Mountains in the south. The country is bordered by Lithuania and Russia to the northeast, Belarus and Ukraine to the east, Slovakia and the Czech Republic to the south, and Germany to the west. Poland also shares maritime boundaries with Denmark and Sweden.
The history of human activity on Polish soil spans thousands of years. Throughout the late antiquity period it became extensively diverse, with various cultures and tribes settling on the vast Central European Plain. However, it was the Polans who dominated the region and gave Poland its name. The establishment of Polish statehood can be traced to 966, when the pagan ruler of a realm coextensive with the territory of present-day Poland embraced Christianity and converted to Catholicism. The Kingdom of Poland was founded in 1025 and in 1569 cemented its longstanding political association with Lithuania by signing the Union of Lublin. The latter led to the forming of the Polish–Lithuanian Commonwealth, one of the largest and most populous nations of 16th and 17th-century Europe, with a uniquely liberal political system that adopted Europe's first modern constitution, the Constitution of 3 May 1791.With the end of the prosperous Polish Golden Age, the country was partitioned by neighbouring states at the end of the 18th century. It regained its independence in 1918 with the Treaty of Versailles and restored its position as a key player in European politics. In September 1939, the German-Soviet invasion of Poland marked the beginning of World War II, which resulted in the Holocaust and millions of Polish casualties. As a member of the Eastern Bloc, the Polish People's Republic proclaimed forthwith was a chief signatory of the Warsaw Pact amidst global Cold War tensions. In the wake of the 1989 events, notably through the emergence and contributions of the Solidarity movement, the communist government was dissolved and Poland re-established itself as a democratic republic.
Poland is a developed market, and a middle power; it has the sixth largest economy in the European Union by nominal GDP and the fifth largest by GDP (PPP). It provides very high standards of living, safety and economic freedom, as well as free university education and a universal health care system. The country has 17 UNESCO World Heritage Sites, 15 of which are cultural. Poland is a member state of the United Nations, the World Trade Organization, NATO, and the European Union (including the Schengen Area).