It was developed in several stages, with Polish and Italian specialists overseeing the changes. It was meant to have a representative but also practical function, namely impressing people and making castle life easier as well as serving as an amphitheatre and a square serving court ceremonies. A major reconstruction of the royal residence took place between 1501 and 1536, and Sigismund the Old himself was the patron of the project. The work was led by two Italians, Francis of Florence and Bartholomew Berrecci, and after their deaths, by Benedict of Sandomierz. The magnificent palace courtyard, with its light cloisters supported by slender arcaded columns, is an excellent example of Renaissance architecture. However, only some fragments of the original have survived to this day. The cloisters, with their very interesting top level, usually had a communicative function, facilitating movement between chambers and different parts of the castle. The entrance to the palace courtyard is through the gate building that had been rebuilt in Renaissance style. On its façade is a stone Piast Eagle with the date 1370, dating from the castle of Casimir the Great in Łobzów. In the hallway are shields with the coats of arms of Poland, Lithuania and the Sforzas sculpted by Berrecci in 1534.