In 1138, after the death of Bolesław III Wrymouth, Poland was divided into districts ruled by local princes. This began a period of feudal fragmentation that lasted for more than 187 years during which Poland was severely weakened due to incessant internal conflicts. The feudal fragmentation ended in 1320 during the reign of Władyslaw I Lokietek.
In 1320, after the end of the feudal fragmentation, during the reign of Władyslaw I Łokietek and his son Casimir III the Great, Poland experienced a period of strong economic development, this period also increased migration to Poland especially of Germans and Jews. The period ended after the death of Casimir the Great and the assumption of the Polish throne by Louis I.
For much of its early history as a Christian state, Poland had to contend with Pomeranians, Prussians, Lithuanians and other Baltic peoples in continuous border wars without clear results or end in sight. After the Teutonic Order conquered and assimilated the Prussians, it began incursions into both Polish and Lithuanian territories. This represented a far greater threat to both Poland and Lithuania, and the two countries united in a defensive alliance by the crowning of the Lithuanian Duke Jogaila as King of Poland (as Władysław II) which led to a major confrontation at the Battle of Grunwald in 1410 and subsequent wars until 1525, when the Order became a vassal to the Polish Crown.
The 17th century saw fierce rivalry between the then major Eastern European powers – Sweden, the Polish–Lithuanian Commonwealth and the Ottoman Empire. At its heyday, the Commonwealth comprised the territories of present-day Poland, and large parts of Ukraine, Belarus, Lithuania, Latvia, Estonia, and Russia, and represented a major European power. However, by the end of the 18th century a series of internal conflicts and wars with foreign enemies led to the dissolution of the Polish–Lithuanian Commonwealth and the partitioning of most of its dependent territories among other European powers.
During the 18th century, European powers (most frequently consisting of Russia, Sweden, Prussia and Saxony) fought several wars for the control of the territories of the former Polish–Lithuanian Commonwealth. At the end of the 18th century, some Poles attempted to defend Poland from growing foreign influence in the country's internal affairs. These late attempts to preserve independence eventually failed, ultimately ending in Poland's partition and the final dissolution of the remains of the Polish–Lithuanian Commonwealth.
Poles unsuccessfully struggled to win back their independence throughout the 19th century. At first, they put their hopes in Napoleon. Later, they tried to ignite national uprisings every now and then – most of them bloodily repressed.
Poles unsuccessfully struggled to win back their independence throughout the 19th century. At first, they put their hopes in Napoleon. Later, they tried to ignite national uprisings every now and then – most of them bloodily repressed.
In the turmoil of the First World War, Poles managed to regain independence and then to expand their territory in a series of local wars and uprisings; only to be occupied again during the next world war.
^Nazi Germany was expelled from Poland, however the Soviet Union remained in control of Poland at the end of the war.
References
^В. Д. Королюк. К вопросу об отношениях Руси и Польши в X веке. АН СССР, Институт славяноведения. Краткие сообщения. № 9. М., 1952. С. 47. Дата обращения: 9 марта 2019. Архивировано 28 января 2021 года.