The first enclosure-type brick castle in Senieji Trakai was built by Grand Duke Gediminas, who transferred the capital of Lithuania from Kernavė to Trakai (today's Senieji Trakai) before 1321. The wedding of Grand Duke Kęstutis and Birutė was held there and it was the birthplace of the Grand Duke Vytautas in 1350.
The castle in Senieji Trakai was destroyed by the Teutonic Order in 1391, subsequently abandoned and never rebuilt as a new castle had been erected in Trakai by Kęstutis. The ruins of the castle were granted to Benedictian monks by Vytautas in 1405. It is presumed that the present monastery building, dating from the 15th century, holds the remains of Gediminas castle.
Archaeological research on the hillfort mound was carried out in 1996–1997. The findings confirmed the existence of a former rectangular masonry castle wall, which had surrounded the hill. It is supposed that the residential buildings had occupied the area near the church and the churchyard.
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.