Poland was united at the end of the tenth century and the beginning of
the eleventh by princes belonging to the house of Piast. and extended for a
short period over a much larger area then shown on the map above. It show
instead the beginning of Poland's age of fragmentation 1138-1320. When Boleslaw III died 1138
was Poland divided between his four sons into autonomous principalities.
To preserve some form of unity was it decided that the central province of
Krakow should always be ruled by the oldest member of the house of Piast,
the so called senior, which had supremacy over the other princes.
But even Krakow was transformed into a hereditary principality 1180-1227
although the princes retained their supremacy over the rest of Poland. Pomerania
was ruled by their own princes and had a loose connection to Poland. Rügen
was completely independent from Poland but became 1325
a part of Pomerania.
Wladyslaw I became king of Poland 1320 and ended Poland's age of
fragmentation. But by then had Silesia and Pomerania been lost to Germany.
Also the rest of Poland's history would be eventful with the Polish state
greatly expanded, wiped out from the map and restored several times.