the official name of the state was "the kingdom of poland and the grand duchy of lithuania" (, , ) and the latin term was usually used in international treaties and diplomacy. in the 17th century and later it was also known as "the most serene commonwealth of poland" (, ), the "commonwealth of the polish kingdom", or the "commonwealth of poland". its inhabitants referred to it in everyday speech as the "rzeczpospolita" (ruthenian: рѣч посполита "rech pospolita", ).