In 1569 the Union of Lublin established the Polish–Lithuanian Commonwealth, and much Ukrainian territory was transferred from Lithuania to the Crown of the Kingdom of Poland, becoming Polish territory de jure. Under the demographic, cultural and political pressure of Polonisation, which began in the late 14th century, many landed gentry of Polish Ruthenia (another name for the land of Rus) converted to Catholicism and became indistinguishable from the Polish nobility. Deprived of native protectors among Rus nobility, the commoners (peasants and townspeople) began turning for protection to the emerging Zaporozhian Cossacks, who by the 17th century became devoutly Orthodox. The Cossacks did not shy from taking up arms against those they perceived as enemies, including the Polish state and its local representatives.