Lucens Castle's strategic location allowed it to control the Broye valley, which was an important transit corridor. Starting in the Middle Ages and until 1536 it was a residence of the Bishop of Lausanne and served to control the Bishop's land in the Broye valley. During the 12th century, the castle was repeatedly destroyed and rebuilt. In 1476, it was destroyed by the Swiss Confederation. In 1536 the valley and the surrounding territory were conquered by Bern. It became the seat of a Bernese bailiwick at the same time. In 1542, the vogt of Moudon moved into the castle.
The castle was enlarged between 1579–86 and served as an arsenal and fortress on the border to Fribourg. In 1798, the Bernese were forced out and the Canton of Léman was formed. Shortly thereafter, the castle became the property of Canton, who sold it 1801 to private individuals. In 1925, it was converted into a Swiss Reformed institute for girls. Between 1965-70, it was the seat of the Conan Doyle Foundation, and is now in private hands.
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.