Vizmburk Castle was founded by Tas or Peter of Skalice and it was mentioned first time in 1279. This noble house with the stirrup in their coat of arms was known already in the 12th century, when their members held the burgrave office in Kladsko. The Vizmburk estate was a fairly large one with the economic centre in the town of Úpice.
In 1330 the the lords of Dubá owned the estate. Jiří of Dubá supported the Hussites movement which resulted in frequent raids of his estate by Silesian troops. The princes and burghers of Silesia and Lusatia eventually sealed the faith of the Vizmburk castle. Instead of arms they used the power of money. In 1447 the castle was bought up and intentionally demolished.
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.