Homburg was first mentioned in documents in 1276. Gottfried I of Sayn from the House of Sponheim (1247-1283/84) transferred his castrum Homburg to the German King Rudolf of Habsburg, in order to place it under his protection. He received the castle back as an inheritance. The castle was the residence of the Counts of Homburg, an imperial fiefdom (Reichsherrschaft).
From 1635 Count Ernst von Sayn-Wittgenstein altered the castle to its present-day appearance. One hundred years later the line of Sayn-Wittgenstein-Berleburg took over its management; the structure then fell into disrepair. Not until 1904 was its decline halted and, in 1926, a museum, founded by Hermann Conrad, took over the premises. Today it is the Museum of Oberbergisches Kreis.
In 1999 during an excavation, a stone keep of about 12.5 metres diameter was uncovered. Experts estimate that it dates to the 11th century. A consequence of this was that the history of the castle had to be reassessed to that time.
At the beginning of 2005 the district council decided to upgrade the castle. Their plans included inter alia the expansion of the 'Red House' (Rotes Haus) and the construction of a central cash desk and toilet area. The old orangery was to be torn down and replaced by a new two-storey administration and exhibition building.
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.