According to legend, Pontivy was founded in 685 AD by an English monk called Ivy who built a wooden bridge across the Blavet, giving the town its name – Pont d’Ivy. The town really began to develop in the 12th century when Viscount Rohan settled there and in the 14th century it became the political and administrative capital of the viscounty.
The main site in Pontivy is its château, which overlooks the River Blavet a short walk from the town centre. The present castle was built in 1485 by Viscount Rohan, whose aristocratic line dates back to 1120. The Rohan family seat has seen plenty of action during its 500-year history including being besieged during the Duchy of Brittany War of Independence in 1488 and taken over by Catholic forces during the French Wars of Religion in 1589. The château, which retains many original features, is open to the public and often stages art exhibitions.
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.