Hachenburg Castle, former seat of the Counts of Sayn, was founded about 1180 by Count Heinrich II of Sayn. Building was finished in 1212 under Count Heinrich III, the founder's son, who was also mentioned as the town's and the castle's first owner. The castle church only arose in the late 15th century and underwent several remodellings until the 18th century.
In 13 October 1654, there was a great fire which burned down the inner town and also the castle. Counts Salentin von Manderscheid and Georg Friedrich von Sayn-Hachenburg undertook to build the town anew, and also the castle, although this time as a Baroque structure. The sweeping Baroque castle was built to architect Julius Ludwig Rothweil's plans between 1715 and 1746. It has had many owners over the last century. For a few decades, however, it has been the seat of Deutsche Bundesbank’s training centre and professional college.
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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.