The Palace of the Grand Dukes of Lithuania (Lithuanian: Lietuvos Didžiosios Kunigaikštystės valdovų rūmai Vilniaus žemutinėje pilyje, Polish: Zamek Dolny w Wilnie) is a palace in Vilnius, Lithuania. It was originally constructed in the 15th century for the rulers of the Grand Duchy of Lithuania and the future Kings of Poland. The palace, located in the lower castle of Vilnius, evolved over the years and prospered during the 16th and mid-17th centuries. For four centuries the palace was the political, administrative and cultural centre of the Polish-Lithuanian Commonwealth.