Poland is bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian Enclave and exclave, to the north.  
The establishment of a Polish state is often identified with the adoption of Christianity by its ruler Mieszko I of Poland in 966, over the territory similar to that of present-day Poland. The Kingdom of Poland (1025-1385) was formed in 1025.
Poland regained its independence as the Second Polish Republic in 1918. Two decades later, in September 1939, it was invaded by Nazi Germany and the Soviet Union, triggering World War II. Over six million Polish citizens died in the war. Poland reemerged several years later within the Soviet Union sphere of influence as the People's Republic of Poland in existence until 1989.
During the Revolutions of 1989, communism rule was overthrown and soon after, Poland became what is constitutionally known as the"Third Polish Republic".  
Since the end of the communist period, Poland has achieved a very high ranking in terms of human development and the standard of living. Besides that, it has managed to preserve much of its Culture of Poland, despite the vast destruction the country experienced in World War II and during the years of communist neglect.