Horneck castle was built around 1200 and was given to the Teutonic Order by Konrad von Horneck in 1438, thereby making it the seat of the 'Deutschmeister' (German Master) until it was destroyed in 1525 by fire during the German Peasants' War. Despite reconstruction shortly after Horneck Castle's destruction, Mergentheim became the new headquarters for the Teutonic Order in that region in 1527.
As of 2006, the castle was occupied by an altenheim (a nursing home for the elderly) as well as the Transylvanian Museum (dedicated to the protection, preservation and documentation of the cultural heritage of the Transylvanian Saxons and of their coexistence).
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.