Sarmatism (or Sarmatianism; Polish: Sarmatyzm; Lithuanian: Sarmatizmas) was an ethno-cultural ideology within the Polish–Lithuanian Commonwealth. It was the dominant Baroque culture and ideology of the nobility (szlachta) that existed in times of the Renaissance to the 18th centuries. Together with the concept of "Golden Liberty", it formed a central aspect of the Commonwealth's culture and society. At its core was the unifying belief that the people of the Polish–Lithuanian Commonwealth descended from the ancient Iranian Sarmatians, the legendary invaders of contemporary Polish lands in antiquity.