The St. Mary Magdalene's Church, dating from the middle of the 13th century, originally served as the parish church for the Hungarian citizens of the town (the Mátyás Church was for the use of the town’s German citizens). During the 14th and 15th centuries it was enlarged several times. During the first-half of the Turkish occupation it remained the only Christian church in the Castle; during the second-half it was converted into a mosque. Following the defeat of the Turks in 1686 it was given back to the Franciscan Order, who demolished most of the church except for the tower, and used the stones to build a new single-nave church, in the Baroque style. As a result of the damage sustained by the church during the 2nd World War, the nave was demolished and only the Gothic style tower was restored. The ruins behind the church have been used to form an exhibition of the history of the church. In 1792 Emperor Francis I, King of Hungary, was crowned in the church.
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.