Oliva, Peace of, 1660, treaty signed at Oliva (now a suburb of Gdańsk) by Poland and Sweden. John II of Poland renounced the theoretical claim of his line to the Swedish crown, which his father, Sigismund III, had in practice lost in 1599. Poland furthermore confirmed Sweden in possession of N Livonia. Frederick William, elector of Brandenburg, was recognized in full sovereignty over Prussia (later known as East Prussia) but in turn confirmed Pomerelia (later West Prussia) as Polish.