Uniejów Castle castle was built between 1360-1365 on the site of a former wooden fortress, destroyed after a raid by the Teutonic Knights in 1331. The initiator of the construction of the castle was Gniezno's Archbishop Jarosław Bogoria Skotnicki, one of the closest associates to Casimir III the Great.
The building was greatly expanded and modernised between 1525-1534, when after a fire most of the castle's Gothic characteristics had gone. The stronghold had ended's its militaristic significance in the seventeenth century, when the castle became a residence. In 1836 the castle was taken over by the House of Toll, an Estonian family. In 1848, Aleksander Toll had reconstructed the castle into a Classical architectural style. The castle in Uniejów is a prime example of accretion of architectural styles.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.