Château de Talmont was founded by the Count of Poitou in the 10th century and the first documentary records appear between 1040 and 1046. In 1138 the castle was held by Joscelin de Lezay, who was attacked by Louis VII; despite being considered invulnerable because it could be resupplied from the sea, the castle was burnt by the king. Talmont passed on to the Mauléons by the 1140s, but in 1182 Richard I of England became the lord of Talmont; he remained in control of the castle until his death in 1199, when it was returned to the Mauléon family.
The castle was enlarged during by the King Richard I of England with round towers, curtain wall and new gate. Most of the castle was demolished in the 17th century.
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.