The area surrounding Nafplio has been inhabited since ancient times, but few signs of this, aside from the walls of the Acronauplia, remain visible. Subsequently, Byzantines, Franks, Venetians, and Turks added to the fortifications. It became a place of considerable importance, and has continued so down to the present day. In the time of the Crusades it first emerges from obscurity. Nafplio was taken in 1212 by French Crusaders of the Principality of Achaea. It became part of the lordship of Argos and Nauplia, which in 1388 was sold to the Republic of Venice, who regarded it as one of their most important places in the Levant. During the subsequent 150 years, the lower city was expanded and fortified, and new fortifications added to Acronauplia.
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.