Between 1115 and 1118 the Augustinian monastery was established in Sankt Märgen by Count Bruno von Haigerloch-Wiesneck, Chancellor of Henry V and Provost of Straßburg, as competition to the Zähringen-founded Benedictine monastery of St. Peter auf dem Schwarzwald. The town and the monastery were dependent upon each other for many years. In 1716 a two-steepled Baroque monastery church was built, and the life of the community underwent a revival, until 1806 when the monastery was given up.
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.