The term Polish–Lithuanian Union refers to a series of acts and alliances between the Kingdom of Poland and the Grand Duchy of Lithuania that lasted for prolonged periods of time and led to the creation of the Polish–Lithuanian Commonwealth—the "Republic of the Two Nations"—in 1569 and eventually to the creation of a short-lived unitary state in 1791.
O termo "unión polacolituana" refírese a unha serie de actos e alianzas entre o Reino de Polonia e o Gran Ducado de Lituania que levou á creación da unión polacolituana — a "República das Dúas Nacións" — en 1569 e eventualmente á creación dun estado unitario en 1791.