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The famous Theodosian Walls of Constantinople (Θεοδοσιανά τείχη) protected the city for over 1,000 years. Today, they separate the Zeytinburnu and Fatih districts of Istanbul.
Brief History of the Theodosian Walls of Constantinople
The Theodosian Walls of Constantinople were completed during the reign of Emperor Theodosius II. Construction started in 404 and lasted until 413. The walls suffered damage due to earthquakes on September 25, 437; November 6, 447; and again in January 448. With Attila the Hun moving towards the city, Theodosius II ordered his praetorian prefect, Constantinus, to repair and strengthen the walls and towers. It took only 60 days.
The walls successfully defended the city against several sieges led by the Avars, Slavs, Sassanids, Arabs of the Umayyad Caliphate, Bulgarians, Rus’, Crusaders, and Ottomans. They were only breached three times: during the Latin Sack of Constantinople in April 1204; the recapture of Constantinople by Alexios Strategopoulos (d. 1275) on July 25, 1261; and by Mehmed the Conqueror during the Fall of Constantinople on May 29, 1453.
The Theodosian Walls remained intact throughout most of the Ottoman Empire. They fell into disrepair over time and sections were dismantled in the 19th century. A restoration program began in the 1980s and many sections were repaired and rebuilt. In 1985, the walls were included in the UNESCO World Heritage listing for the Historic Areas of Istanbul.
Features of the Theodosian Walls of Constantinople
The Theodosian Walls ran for 5.7 kilometers (3.5 miles) from north to south, stretching from the Walls of Blachernae (now Ayvansaray), near the Palace of the Porphyrogenitus (Tekfur Sarayı), to the Marmara Sea. They consisted of an inner and outer wall separated by a terrace, followed by an outer terrace, a low wall, and a moat. There were 9 main gates, a number of smaller gates, and 192 towers.
The southern end of the Theodosian Walls is the Tower of Basil and Constantine (Πύργος Βασιλείου και Κωνσταντίνου), which now stands alone next to Kennedy Avenue (Kennedy Caddesi) on the Marmara Sea. The Turkish name is the Marble Tower (Mermer Kule).
Inner Wall
The inner wall (μέγα τεῖχος, or great wall) was between 4.5 to 6 meters thick and 12 meters high. It was strengthened with 96 towers, which were 15 to 20 meters high and 10 to 12 meters wide. Each tower had a battlemented terrace on top and most had two chambers inside.
Outer Wall
The outer wall (ἔξω τεῖχος) was roughly 2 meters thick and 8.5 to 9 meters high. It also contained 96 towers, which were 12 to 14 meters high and 4 meters wide. Only 62 of those towers survive today.
Terraces
Between the inner and outer walls was a terrace called a peribolos (περίβολος), which was between 15 and 20 meters wide. The outer wall and moat were separated by an outer terrace called the exo parateichion (ἔξω παρατείχιον), which was about 15 meters wide and contained a paved road for troop movements.
Moat
Finally, the moat (σοῦδα) was about 20 meters wide and 10 meters deep. There was a 1.5 meter high wall on its inner side serving as the first line of defense. The moat and terraces are now used as vegetable gardens.
Gates on the Theodosian Walls of Constantinople
As mentioned previously, there are nine gates on the walls. Because the Byzantines used names rather than numbers to identify the gates, and the Ottomans used different names, only the location of three gates can be established (Gate of Charisius, Gate of Rhegion, and the Golden Gate). In the sections below, I’ll provide details on some of the gates based on theories by scholars. I’ll list the gates from north to south.
Gate of Charisius
The Gate of Charisius (Χαρισίου πύλη) was the second most important gate after the Golden Gate. It was named for a nearby Byzantine monastery and sits at the highest point of the old city at 77 meters. Constantine XI established his command there, and Mehmed the Conqueror made his entrance into Constantinople through the gate on May 29, 1453. Today, the gate is known as Edirnekapı (Edirne / Adrianople Gate), and the Edirnekapı area sits inside the gate.
5th Military Gate
After a few minor gates is the 5th Military Gate (Πόρτα τοῦ Πέμπτου), which sits between towers 77 and 78. It’s named after the quarter of the Pempton (The Fifth) and is heavily damaged. The Ottomans decisive breakthrough took place at this gate on the morning of May 29, 1453. Today, it’s called Sulukule Kapısı (Water Tower Gate) or Hücum Kapısı (Assault Gate).
Gate of St. Romanus
Further south is the Gate of St. Romanus (Πόρτα τοῦ Ἁγίου Ρωμάνου), which was named after a nearby church, sits between towers 65 and 66. It was the second largest gate after the Golden Gate. Scholars believe Constantine XI was killed at the Gate of St. Romanus. Today, the gate is called Topkapı (Cannon Gate), because the great Ottoman cannon, the Basilic, was placed opposite this gate during the Fall of Constantinople. The Topkapı neighborhood sits inside the gate.
Gate of Rhegion
Next is the Gate of Rhegion (Πόρτα Ῥηγίου), which was also known as the Gate of Rhesios (Πόρτα Ῥησίου) or the Gate of Rhousios (Πόρτα τοῦ Ῥουσίου). It sits between towers 50 and 51. This gate was repaired in 448 by the Hippodrome faction of the Reds. It’s the best preserved gate on the walls and has largely kept its 5th century appearance. Today, it’s known as Yeni Mevlevihane Kapısı (New Mevlevi Lodge Gate).
Gate of the Spring
The Gate of the Spring (Πύλη τῆς Πηγῆς) led to the Monastery of the Life-giving Spring, now in the Balıklı neighborhood of Zeytinburnu. It sits between towers 35 and 36, and the southern tower and bears an inscription dated 1439 commemorating repairs carried out under John VIII Palaiologos. It was also known as the Selymbria Gate (Πύλη τῆς Συλημβρίας) and was possibly the Gate of Melantias (Πόρτα Μελαντιάδος). On July 25, 1261, Alexios Strategopoulos entered Constantinople through this gate to retake the city from the Latins. In 1998 a basement with 4th/5th century reliefs and tombs was discovered underneath the gate. Today, it’s know as Silivri Kapısı (Silivri Gate) and the Silivrikapı neighborhood is inside the gate.
Xylokerkos Gate
Continuing south is the Xylokerkos Gate (Πύλη τοῦ Ξυλοκέρκου), also known as the Xerokerkos Gate (Πύλη τοῦ Ξηροκέρκου). It sits between towers 22 and 23 and was named after a wooden circus (amphitheater) that was located outside the gate. The gate is 5 meters wide.
According to Byzantine historian Nikitas Choniates (1155-1217), the Xylokerkos Gate was walled off in 1189 by Emperor Isaac II Angelos, who believed a prophecy stating Holy Roman Emperor Frederick Barbarossa would enter through the gate to take the city. The gate was reopened in 1346 and closed again shortly before 1453. It remained closed until 1886.
The gate is now known as Belgrad Kapısı (Belgrade Gate) because Süleyman the Magnificent resettled Serbian artisans there after he conquered Belgrade in 1521. The small Belgradkapı neighborhood straddles both sides of the gate.
Little Golden Gate
Just before the Yedikule Fortress is the Little Golden Gate (Μικρή Χρυσή Πύλη), which was a minor gate used for everyday traffic. Today, it’s known as Yedikule Kapısı (Yedikule Gate) and leads to the Yedikule neighborhood.
Golden Gate
Yedikule Fortress encompasses the Golden Gate (Χρυσή Πύλη / Altınkapı), which was the most important gate on the Theodosian Walls. It was the main ceremonial entrance to Constantinople and was built with polished white marble. There were actually 3 arched gates flanked by 2 large towers, corresponding to towers 9 and 10, and it was decorated with several statues.
The Small Golden Gate, which sits in front of the Golden Gate, was built later in the 5th century to strengthen the defensive line. It has a single gate and was decorated with 12 tablets on marble frames featuring mythological themes. The tablets, which once belonged to an ancient structure, have since disappeared. The Small Golden Gate was repaired in 1838 during the reign of Mahmud II. His tughra and the Ottoman coat of arms were placed on the outer arch.
The Golden Gate opened to the Via Egnatia, which was an ancient Roman road built in the 2nd century BC. It led from Constantinople to Thessaloniki and onto Dyrrachium (now Dürres, Albania).
According to a Greek prophecy, when the Ottomans entered the city during the Fall of Constantinople, an angel appeared and rescued Constantine XI. The angel turned the Emperor into marble and placed him in an underground cave near the Golden Gate, where he would rise one day to retake the city for Christianity. The Ottomans had the gate sealed to prevent the prophecy from coming true, and it’s still sealed to this day.
Visitor Centers on the Theodosian Walls of Constantinople
In 2020, the city began an extensive restoration of portions of the Theodosian Walls. Visitor centers opened at Mevlanakapı and Silivrikapı in September 2022, including the Silivrikapı Roman Hypogeum, followed by Belgradkapı in 2024. Other sections are planned to open at Edirnekapı and Sulukulekapı.
These areas provide detailed information on the walls as well as unique opportunities for exploration. When completely finished, they’ll host cultural and artistic events. Admission to each visitor center is free (as of March 2025).
Belgradkapı Visitor Center
So far, I have been able to visit the Belgradkapı Visitor Center (Belgradkapı Ziyaretçi Merkezi), which is open daily from 10am to 6pm. There are three shelters with small libraries inside that also serve coffee and tea. The section on the north side of the gate includes a restored area between towers 23 and 26. There’s one shelter in that section.
The southern section runs between towers 15 and 22. It contains two shelters and was still partially under construction when I visited.
At the entrance, there’s a stairway leading up to a small section of the outer wall. It gives you the opportunity to see the walls from a unique perspective. There are also metal stairways you can climb to see different angles of the towers.
