Kingdom of Poland

State · 962–1449 CE · at its largest around 1003 CE

Polish state of the Piast and later Jagiellonian dynasties, which adopted Christianity under Mieszko I in 966 and became a kingdom with Boleslaw I's coronation in 1025.

On its lands while it lasted

Otto the Great (912 CE – 973 CE): German king who defeated the Magyars and was crowned emperor in Rome in 962; he was buried in Magdeburg.
Baptism of Poland (966 CE): Duke Mieszko I accepted baptism, bringing Poland into Latin Christendom; the event is traditionally seen as the founding of the Polish state.
Stephen I of Hungary (c. 975 CE – 1038 CE): First king of Hungary, crowned in 1000 or 1001, who converted his people to Christianity; venerated as Saint Stephen.
Gdańsk (997 CE): Capital of Free City of Danzig (1920–1939).
Wroclaw (1000 CE): Capital of Duchy of Silesia (1139–1304), Duchy of Wroclaw (1169–1201).
Olomouc (1017 CE): Capital of Margraviate of Moravia (1385–1414).
Gniezno (c. 1025 CE): Capital of Kingdom of Poland (1025–1385).
Plock (c. 1139 CE): Capital of Duchy of Masovia (1139–1351).
Sandomierz (c. 1139 CE): Capital of Duchy of Sandomierz (1139–1304).
Poznań (c. 1139 CE): Capital of Duchy of Greater Poland (1139–1304).
Munich (1158 CE): Capital of Duchy of Bavaria (1505–1805), Kingdom of Bavaria (1806–1870).
Opole (c. 1177 CE): Capital of Duchy of Opole (1177–1304).
Bytom (1200 CE): Capital of Duchy of Bytom (1285–1304).
Dresden (1206 CE): Capital of Electorate of Saxony (1547–1805), Kingdom of Saxony (1806–1808).
Mongol invasion of Rus’ and Europe (1236–1242 CE): Mongol armies under Batu and Subutai conquered Volga Bulgaria and the Rus’ principalities, destroyed Kiev in 1240, and in 1241 won at Legnica and Mohi, before withdrawing from Central Europe in 1242.