The origins of Randeck Castle are unknown, but in the tenth century Duke Arnulf may have built built the first medieval fortress on the hill in order to protect the land against the raids of the Hungarians.
Baron von Rotteneck is said to have built the castle in the 11th century. In the 13th century the Counts of Abensberg took possession of the castle. The owner Jack von Abensberg was known as robber baron and the city of Nuremberg waged war against him. In 1446 his castles were demolished and burnt down. Niclas, the last Count of Abensberg, was killed in 1485 in a feud with a neighbouring family.
The castle was attacked by Swedish army during the Thirty Years´ War. Both castle and convent were destroyed. In 1838 a large part of the castle just collapsed after heavy rainfalls.
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.