Eberbach Castle consists of three separate castles situated about 160 metres high above the river Neckar. It is assumed that the front castle was built in the last quarter of the 12th century, the middle castle ca. 1200 and the rear castle in the second quarter of the 13th century. In 1227 King Henry VII was given Eberbach Castle as a fief by the Bishop of Worms. Presumably the castles remained in the possession of the empire until 1330. After that, the castles were pledged to the palsgraves who subsequently used them as a bailiwick of the Electoral Palatinate.
In 1402 Ruprecht III of the Palatinate pledged the town and the castles to the knight Hans von Hirschhorn. In 1403 he obtained permission from the king to demolish and raze the castle, since presumably it was not of any use, but only entailed costs. He thus got rid of competitors for his castles in Hirschhorn and Zwingenberg. By and by the ruins were dismantled and their stones used for building projects in Eberbach, in particular for building walls to fend off game in order to protect the fields lying next to the woodland. Excavations in 1908-09 and 1927-28 exposed the remains of the front and middle castles, and some parts were reconstructed. From 1959-1963 systematic scientific research was carried out, and the rear castle was reconstructed in parts.
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.