Poland ((ポーランド語:Polska) ), officially the Republic of Poland (, ), is a country in Central Europe, bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine and Belarus to the east; and the Baltic Sea, Kaliningrad Oblast (a Russian exclave) and Lithuania to the north. The total area of Poland is ,〔 making it the 71st largest country in the world and the 9th largest in Europe. With a population of over 38.5 million people,〔 Poland is the 34th most populous country in the world,〔 the 8th most populous country in Europe and the sixth most populous member of the European Union, as well as the most populous post-communist member of the European Union. Poland is a unitary state divided into 16 administrative subdivisions.
The establishment of a Polish state can be traced back to 966, when Mieszko I,〔 ruler of a territory roughly coextensive with that of present-day Poland, converted to Christianity. The Kingdom of Poland was founded in 1025, and in 1569 it cemented a longstanding political association with the Grand Duchy of Lithuania by signing the Union of Lublin. This union formed the Polish–Lithuanian Commonwealth, one of the largest and most populous countries of 16th and 17th-century Europe.〔Norman Davies, ''Europe: A History'', Pimlico 1997, p. 554: ''Poland-Lithuania was another country which experienced its 'Golden Age' during the sixteenth and early seventeenth centuries. The realm of the last Jagiellons was absolutely the largest state in Europe''〕 The Commonwealth ceased to exist in the years 1772–1795, when its territory was partitioned among Prussia, the Russian Empire, and Austria. Poland regained its independence (as the Second Polish Republic) at the end of World War I, in 1918.
In September 1939, World War II started with the invasions of Poland by Nazi Germany and the Soviet Union (as part of the Molotov–Ribbentrop Pact). More than six million Polish citizens died in the war.〔Project in Posterum, (Poland World War II casualties. ) Retrieved 20 September 2013.〕〔Tomasz Szarota & Wojciech Materski, ''Polska 1939–1945. Straty osobowe i ofiary represji pod dwiema okupacjami'', Warsaw, IPN 2009, ISBN 978-83-7629-067-6 ((Introduction online. ))〕 In 1944, a Soviet-backed Polish provisional government was formed which, after a falsified referendum in 1947 took control of the country and Poland became a satellite state〔Rao, B. V. (2006), History of Modern Europe Ad 1789-2002: A.D. 1789-2002, Sterling Publishers Pvt. Ltd.〕 of the Soviet Union, as People's Republic of Poland. During the Revolutions of 1989 Poland's Communist government was overthrown and Poland adopted a new constitution establishing itself as a democracy.
Despite the vast casualties and destruction the country experienced during World War II, Poland managed to preserve much of its cultural wealth. There are 14 heritage sites inscribed on the UNESCO World Heritage〔 and 54 Historical Monuments and many objects of cultural heritage in Poland. Since the end of the communist period, Poland has achieved a "very high" ranking in terms of human development,〔 as well as gradually improving economic freedom.〔http://www.heritage.org/research/reports/2015/01/asia-pacific〕 Poland is the sixth largest economy in the European Union and among the fastest rising economic states in the world. The country is the sole member nation of the European Union to have escaped a decline in GDP and in recent years was able to create probably the most varied GDP growth in its history.〔http://www.oanda.com/currency/iso-currency-codes/PLN〕 Furthermore, according to the Global Peace Index for 2014, Poland is one of the safest countries in the world to live in.〔http://www.thenews.pl/1/6/Artykul/211421,Whats-Up-Poland-a-safe-country〕
(詳細はethnonyms for the Poles〔 include endonyms (the way Polish people refer to themselves and their country) and exonyms (the way other peoples refer to the Poles and their country). Endonyms and most exonyms for Poles and Poland derive from the name of the West Slavic tribe of the Polans (''Polanie'').
The origin of the name ''Polanie'' itself is uncertain. It may derive from such Polish words as ''pole'' (field).〔 The early tribal inhabitants denominated it from the nature of the country. Lowlands and low hills predominate throughout the vast region from the Baltic shores to the foothills of the Carpathian Mountains. "Between the Alps, Hungary, and the ocean, lies Poland, which is called in their native tongue Campania" ((ラテン語:"Inter Alpes Huniae et Oceanum est Polonia, sic dicta in eorum idiomate quasi Campania")) is the description by Gervase of Tilbury in his ''Otia imperialia'' ("Recreation for the Emperor") of 1211. In some languages, the exonyms for Poland derive from another tribal name, Lechites (''Lechici'').