Schloss Oranienstein is one of the palaces of the House of Orange-Nassau, sited at Diez on the Lahn. It was built on the ruins of Dierstein Abbey between 1672 and 1681 for Countess Albertine Agnes of Nassau after she was widowed.
After the French Republican invasion destroyed the Dutch Republic in 1795, stadtholder William V, Prince of Orange and his family first fled to England, before settling in Oranienstein for several years. Here, William and his son William Frederick issued the Oranienstein Letters, recognising the Batavian Republic and renouncing their stadtholderate and territorial claims in the Netherlands in return for financial and territorial compensation elsewhere, granted by First Consul Napoleon Bonaparte.
After the annexation of the Duchy of Nassau by Prussia in 1866, the palace was given to the Prussian army the following year. It is still today occupied by the Bundeswehr, together with adjacent barracks, but also houses a museum.
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.