Its predecessors, the kingdom of Poland and the Grand Duchy of Lithuania, had centuries of history beforehand. Poland–Lithuania was a beacon for liberty in a time when absolute monarchy was the norm in Europe. The union was known for religious tolerance, ethnic diversity, and parliamentary rule. While formally called a Res Publica in Latin (Rzeczpospolita in Polish and Respublika in Lithuanian), it was not a republic in the modern sense, but had a unique form of government: The head of state was simultaneously King of Poland, Grand Duke of Lithuania and President of the Republic. He was elected for life by the numerous members of the aristocracy and gentry (Szlachta) who made up more than 10 percent of the total population (much more than in other European countries of that time). The elected monarchs came either from the Polish high nobility (magnates) or from foreign dynasties like the Swedish House of Vasa and later the Electors of Saxony who reigned both countries in personal union for much of the 18th century (the "Saxon era"). Bribes often decided who was elected king. The powers of the respective monarch were very limited, while the nobles enjoyed "Golden Liberty". Each member of parliament (Sejm) had a veto right, making decisions very difficult.
At the end of the 18th century, the country was partitioned between three rising great powers; the Russian Empire, the Austro-Hungarian Empire and Prussia (later the German Empire) throughout the 19th century. Poland and Lithuania were devastated in the crossfire of two world wars, were subjugated to the Soviet Union, and achieved functional independence only with the 1980s revolutions. However, Polish-Lithuanian rule was instrumental in the formation of separate Ukrainian and Belarusian national identities from Russia, and the formation of distinct Ukrainian and Belarusian languages.
- 1 Kraków. The traditional capital of the Kingdom of Poland and the whole Commonwealth.
- 2 Warsaw. De facto capital for most of the commonwealth's history.
- 3 Lublin. Located between Kraków and Vilnius, the union between Poland and Lithuania was signed here in 1569. Moreover, Lublin was the seat of the Polish Crown Tribunal (highest appeal court) during spring and summer. Old town with castle, national museum and cathedral.
- 4 Piotrków Trybunalski. One of the royal cities, first seat of the Sejm (parliament) and seat of the Polish Crown Tribunal during autumn and winter.
- 5 Gdańsk. Chief seaport.
- 2 Oliwa. Place of a 1627 naval battle against Sweden and the 1660 peace treaty ending the Second Northern War ("Swedish Deluge"). Cathedral and rococo palace.
- 6 Poznań. Capital of the Greater Poland Province.
- 7 Zamość. The Renaissance old town is a World Heritage site.
- 9 Grodno. Secondary capital of Lithuania, alternate seat of the Sejm and the Lithuanian Tribunal. During the 1793 Grodno Sejm, the deputies submitted to Russia, quashed the constitution and accepted the second partition of Poland.
- 10 Minsk. Was the capital of a Polish-Lithuanian voivodeship. The baroque Catholic cathedral from that period is extant. Minsk's city hall is a modern reconstruction of the Baroque-Neoclassical one from the Polish-Lithuanian era.
- 3 Mir Castle Complex. Late-Gothic castle of Polish-Lithuanian magnates.
- 4 Nesvizh Castle. Residence of the Radziwiłł family, one of the wealthies and most powerful clans of Poland-Lithuania.
- 11 Jelgava. Capital of the Duchy of Courland and Semigallia that was part of the Polish-Lithuanian Commonwealth. A Baroque palace and the Academia Petrina stand witness of that era.
Due to its history as part of the Polish-Lithuanian Commonwealth and later, the Austro-Hungarian Empire, the westernmost part of Ukraine has a Catholic majority, in contrast to the rest of majority-Eastern Orthodox Ukraine.
- 12 Lviv. Used to be the capital of the Ruthenian Voivodeship of Poland-Lithuania. Many Renaissance and Baroque buildings in the city centre are evidence of that period.
- 13 Kamianets-Podilskyi (Kamieniec Podolski). Was a major fortress city in the Polish Voivodeship of Podolia due to its strategic location in a bend of the deeply incised river Smotrych. The 16th-century fortress as well as the picturesque old town with churches of different denominations and a late-Baroque triumphal gate celebrating Polish king Stanisław II August are remains of that era.
- 14 Kyiv. Kyiv, the former capital of the Rus', and today the capital of Ukraine, was conquered from the Golden Horde by the Duchy of Lithuania in 1362, and subsequently became the Kiev Voivodeship in 1471. It remained under the rule of Lithuanian princes until the formation of the Polish-Lithuanian Commonwealth in 1569, when it was transferred to the Polish crown. It was then ceded to the Russian Empire in 1667. The hill known as Zamkova Hora is the former site of a Lithuanian castle, and a historical landmark in the city. The neighbourhood of Podil was the city centre under Lithuanian rule.
- 15 Moscow. Moscow was occupied by the Polish-Lithuanian Commonwealth between 1610-1612, following its victory over Tsardom of Muscovy at the Battle of Klushino, coinciding with a period of anarchy in Russian history known as "the Time of Troubles". Cossacks under the command of Prince Dmitry Trubetskoy besieged the city and had driven the Polish-Lithuanian forces out of most of the city by May 1611, the exception being Kitay-Gorod and The Kremlin. The last Polish-Lithuanian troops holed up in the Kremlin surrendered to the Cossacks on 7th November 1612, the anniversary of which is celebrated in Russia as Unity Day every year.