The Early Brick Castle stood on the site of the Grand Courtyard from the end of the 13th century; the castle’s contours are marked in red granite inlaid in the paving of the courtyard, while its remnants are on display in the underground expositions. In the first half and middle of the 16th century, during the reigns of Sigismund the Old (1506–1548) and his son Sigismund Augustus (1544/1548–1572), the Palace of the Grand Dukes of Lithuania was built on this site.
Its four wings were positioned around an enclosed inner Grand Courtyard. The courtyard was paved with field boulders, with a well in the south east corner, near the stairwell tower. The south wing and part of the east wing were built back in the early 16th century and still retained some Gothic characteristics. This L-shaped layout of the wings can be associated with the Aula regia antiqua, or Old Royal Palace style. Other Renaissance wings were added in the mid-16th century. By the early 17th century, the palace was remodelled in the Baroque style. It is believed that the south wing served as the representational space of the palace. At its western end, and what later became the west wing, one could find the rulers’ apartments. The east wing, the northern end of which is sometimes referred to as Bona Sforza’s tower, must have housed the queen’s apartments. The north west wing could have been associated with the so-called New Palace (Domus nova). The kitchen was located at its northern end.
In the middle of the 17th century, during the years of war, the palace was plundered, damaged and then competely destroyed in 1799–1801. Investigation of the palace and Grand Courtyard began in 1987, while in 2002–2018 it was reconstructed and a museum was opened on the site. Various events are held in the Grand Courtyard.
