Founding of the Polish state
Events
in wich Poland was/is involved

Founding of the Polish state

Throughout Late Antiquity, the lands of present day Poland were populated by many different cultures, known from archeological research, but many still of uncertain ethnicity or linguistic affiliation. Slavic, Celtic, Germanic and Baltic peoples were among the prominent groups. Poland began to form into a recognizable unitary and territorial entity around the middle of the tenth century under the Piast dynasty.

The first Polish state was created in 966, within territory very similar to the present boundaries of Poland. Poland's first historically documented ruler was Mieszko I. Poland became a kingdom in 1025. Mieszko was baptized in 1066. After that he was recognized as king of an independent state by the Pope and by the German emperor.
More information

Mieszko I,painted by Jan Matejko

Polonica stamps:

Brazil 1967, 12 III
 USA 1966, 30 VII
 Vatican City 1966, 03 V