Birseck Castle is also called Vordere Burg Birseck and is one of four castles on a slope called Birseck that confines the plain of the Birs river. Burg Reichenstein sits on a higher slope to the north.
The origins of the castle probably date back to the age of Counts of Frohburg in the 12th century. Bishop Lüthold of Basel bought the castle hill from the Niedermünster monastery in 1239 and built the present castle in 1243/44.
In the 15th and 17th centuries Birseck was expanded. It served during the Counter-Reformation as a residence for Bishop Christoph Blarer (around 1600). In the middle of the 18th century, a stone bridge replaced the drawbridge.
In the 18th century, the castle was poorly maintained. In 1763 , Karl von Andlau moved his county seat from the castle down to the village. During the French Revolution in 1793, some parts of the English garden, the Ermitage and the building of the castle were set on fire or destroyed by drunken peasants. In 1808, Conrad von Andlau and Canon Heinrich von Ligerz acquired the ruins. The tower and the chapel were restored to their original state in the neo-Gothic style.
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.