Casimir III realized that the nation needed a class of educated people, especially lawyers, who could codify the country's laws and administer the courts and offices.His efforts to create an institution of higher learning in Poland were finally rewarded when Pope Urban V granted him permission to open the University of Kraków.The Black Death, a plague that ravaged Europe from 1347 to 1351 did not significantly affect Poland, and the country was spared from a major outbreak of the disease.
The ethnicity and linguistic affiliation of these groups have been hotly debated; the time and route of the original settlement of Slavic peoples in these regions lacks written records and can only be defined as fragmented.
The most famous archaeological find from the prehistory and protohistory of Poland is the Biskupin fortified settlement (now reconstructed as an open-air museum), dating from the Lusatian culture of the early Iron Age, around 700 BC.
The Slavic groups who would form Poland migrated to these areas in the second half of the 5th century AD.
In 1109, Prince Bolesław III Wrymouth defeated the King of Germany Henry V at the Battle of Hundsfeld, stopping the German march into Poland.
The significance of the event was documented by Gallus Anonymus in his 1118 chronicle.