Map showing Constantinople and its walls during the Byzantine eraThe Walls of Constantinople are a series of stone walls that have surrounded and protected the city of Constantinople (today Istanbul in Turkey) since its founding as the capital of the Eastern 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.
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, when well manned, they were almost impregnable for any medieval besieger, saving the city, and the Byzantine Empire with it, during sieges from the Avars, Arabs, Rus', and Bulgars, among others (see Sieges of Constantinople). Only the advent of gunpowder siege cannons rendered the fortifications obsolete, resulting in the final siege and fall of Constantinople to the Ottomans on May 29th 1453.
The walls were largely maintained intact during most of the Ottoman period, until sections began to be dismantled in the 19th century, as the city outgrew its medieval boundaries. Despite the subsequent lack of maintenance, many parts of the walls survived and are still standing today. A large-scale restoration programme has been under way in the past twenty years, which allows the visitor to appreciate their original appearance
The restored Gate of Charisius or Adrianople Gate, where Sultan Mehmed II entered the city.
The Second Military Gate or Gate of Belgrade
The sinister Yedikule today
The section of the Theodosian Walls that adjoins the walls of Blachernae, with the Palace of Porphyrogenitus in the background, as they appear today in suburban Istanbul.
3-D Model of the Walls
Sea Walls don´t exist anymore,in the background Hagia Sofia and Hagia Eirene