Monastery of the Holy Spirit (Sviato-Dukhov Monastery) is a female Eastern Orthodox monastery in Vitebsk. The monastery was founded in the 1380s by Duchess Uliana of Tver, wife of Algirdas, Grand Duke of Lithuania. Algirdas ordered to construction of the Cathedral of the Holy Spirit in this monastery. About 1392–1393, after Algirdas' death, Uliania took the vows of schema in her monastery.
From mid-17th century till 1839, the monastery was Greek-Catholic. In 1839, after cancellation of the Union of Brest, it was converted back to Orthodoxy and was soon shut down because of poverty. After the October Revolution the majority of the old monastery's buildings were destroyed.
The monastery was revived in 2001. At present, it owns one building.
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.