Biburg Abbey was a house of the Benedictines founded in 1132 by Konrad and Arbo von Sittling-Biburg. They were sons of the Blessed Berta of Biburg, who donated their castle to the Bishop of Bamberg for the purpose. The foundation was originally a double monastery for both men and women; the nunnery however burnt down in 1258 and was not re-built.
In 1555 the monastery was dissolved and the premises came into lay hands. In 1589 the Jesuit College of Ingolstadt obtained the buildings, which were taken over in 1781 by the Knights Hospitaller. In 1808 the monastery was secularised and passed into the possession of the Bavarian State.
The abbey church has remained mainly unchanged from its inauguration in 1140.
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.