Walls of Constantinople

The walls of Constantinople (Turkish: Konstantinopolis Surları; Greek: Τείχη της Κωνσταντινούπολης) are a series of defensive stone walls that have surrounded and protected the city of Constantinople (modern Fatih district of Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. These walls were among the most complex and elaborate fortifications ever built, and they helped protect the city for many centuries.

Initially built by Constantine the Great, the walls surrounded the new city on all sides, defending it against attacks from both sea and land. Later, in the 5th century, the famous double line of the Theodosian walls was added. Even with the invention of gunpowder siege cannons, these walls remained strong. They saved the city and the Byzantine Empire during many difficult sieges over the years.

Although the walls were mostly kept safe during the time of the Ottoman rule, parts of them were taken down in the 19th century as the city grew. Even so, many sections of the walls still stand today. Since the 1980s, efforts have been made to restore and care for these important remains.

Land walls

Walls of Greek and Roman Byzantium

The city of Constantinople began as Byzantium, founded by Greek settlers from Megara around 658 BC. It was protected by a small wall around an elevated area called the acropolis. This wall had twenty-seven towers and two main gates. Over time, the city changed hands and its defenses were updated.

Constantinian walls

When Constantine the Great made the city his new capital in 330 AD, he built new walls about 2.8 kilometers west of the old ones. These walls had towers and gates to protect the growing city. By the 5th century, the city had grown beyond these walls, but they remained important for many years.

Theodosian walls

The most famous walls were built during the rule of Emperor Theodosius II in the early 5th century. These walls were much stronger and more complex, with two main walls and a wide moat in front. They protected the city for over a thousand years and were a major reason why Constantinople survived many sieges and attacks.

The Theodosian walls stretched for about 5.7 kilometers from the Sea of Marmara to the Golden Horn. They included many gates and towers, with the Golden Gate being the most grand and important. These walls were repaired many times over the centuries, especially after earthquakes, and they remained strong even during the Ottoman siege in 1453.

Walls of Blachernae

Near the Blachernae area, additional walls were built to protect the imperial palace and the city’s northern parts. These walls were connected to the main Theodosian walls and included several gates and towers. They were built at different times and varied in strength and design.

Preservation and restoration work

The walls run through modern Istanbul, with parks along their sides. Modern roads cross through them at intervals. In the 1980s, many parts were restored with help from UNESCO. However, this work has been criticized for damaging historical evidence, using the wrong materials, and poor quality. This was clear during the 1999 earthquakes, when some restored parts fell down but the original walls stayed standing. Pollution and lack of proper care led the World Monuments Fund to add the walls to its 2008 Watch List of the 100 Most Endangered Sites in the world.

Sea walls

The seaward walls enclosed the city along the Sea of Marmara and the Golden Horn. Although the original city of Byzantium had sea walls, the exact date for building the medieval walls is debated. Traditionally, they are attributed to Constantine I, along with the main land wall. The first known reference to their construction comes in 439, when the urban prefect Cyrus of Panopolis was ordered to repair and complete the city walls on the seaward side. This activity is connected to the fall of Carthage to the Vandals, which signaled a naval threat in the Mediterranean.

The sea walls were similar to the Theodosian walls but simpler. They were formed by a single wall, lower than the land walls, with inner circuits near the harbors. Access to the walls facing the Golden Horn was prevented by a heavy chain, installed by Emperor Leo III, stretching across the inlet. On the Marmara coast, strong currents made naval attacks almost impossible.

During its early centuries, Constantinople faced few naval threats. After the wars of Justinian, the Mediterranean became a safe area again. The first naval engagement occurred during the siege by the Avars and the Sasanid Persians. After the Arab conquests of Syria and Egypt, a new naval threat emerged. The sea walls were renovated in the early 8th century under Tiberios III or Anastasios II. Michael II initiated a wide-scale reconstruction, completed by his successor Theophilos, which increased their height. These repairs used extensive resources, as described by Constantine Manasses.

The sea walls proved weak during the siege by the Fourth Crusade, as the Venetians managed to storm them. Following this, Michael VIII Palaiologos took care to heighten and strengthen the seaward walls after the Byzantine recapture of the city in 1261. The installation of the Genoese at Galata across the Golden Horn posed a further potential threat.

Golden Horn Wall

The wall facing the Golden Horn stretched for 5,600 metres from the cape of St. Demetrius to the Blachernae. Most of the wall was demolished in the 1870s during the construction of the railway line. It was built further inland from the shore and was about 10 metres tall. It featured many gates and towers. The northern shore was a major focal point of commerce and contained quarters allocated to foreigners living in the city. Muslim traders had their own lodgings there, and from the time of Alexios I Komnenos, emperors granted extensive trading quarters to various Italian maritime republics.

The known gates of the Golden Horn wall can be traced from the Blachernae eastwards to the Seraglio Point.

Propontis Wall

The wall of the Propontis was built almost at the shoreline, except for harbors and quays, and had a height of 12–15 metres, with thirteen gates, and 188 towers, and a total length of almost 8,460 metres. Several sections of the wall were damaged during the construction of the Kennedy Caddesi coastal road in 1956–57. The wall’s proximity to the sea and the strong currents of the Propontis meant that the eastern and southern shores were safe from attack, but the walls had to be protected against the sea itself.

From the cape at the edge of the ancient acropolis of the city to the Marble Tower, the Propontis Wall and its gates went as follows:

The first gate, now demolished, was the Eastern Gate or Gate of St. Barbara, after a nearby church. Unique among the seaward gates, it was flanked by two large towers of white marble. It served as the entry-point for emperors on triumphal returns.

Next was the gate known as Değirmen Kapı, whose Byzantine name is unknown. Close by stood the great Tower of Mangana, intended to hold one end of a chain to close off the Bosphorus. The next gate is now known as Demirkapı, an Ottoman-era structure. A Greek name is not known, and it is not known whether a gate stood there in Byzantine times.

Further south are two further gates, the Balıkhane Kapısı and Ahırkapısı, named after buildings inside the Topkapı Palace they led to. Their Byzantine names are unknown.

The next gate was the gate of the imperial Boukoleon Palace, known in Byzantine times as the Gate of the Lion after the marble lions that flanked its entrance, as well as Gate of the Bear after depictions of that animal at the quay.

To the west of the Bucoleon Palace lies the Church of SS. Sergius and Bacchus, and the first of the harbours of the city's southern shore, that of the Sophiae.

The next harbour to the west is the large Harbour of Eleutherius or Theodosius, in the area known as Vlanga.

Further to the west, where the shoreline turns sharply south, stood the Gate of Psamathia, leading to the suburb of the same name.

Further south and west lies the gate known today as Narlıkapı, prominent on account of its proximity to the famed Monastery of Stoudios.

Garrisons of the city

During the time of the Byzantine Empire, the city's defense force was small. The main groups were the imperial guards and a small city watch called the pedatoura or kerketon, led by the urban prefect. If danger came, the field armies in the provinces would try to stop it before it reached the city.

In the early years, the imperial guard included groups called the Excubitores and Scholae Palatinae. Later, Emperor Justinian II created new guard units to protect the imperial palace. In the 8th century, emperors formed special elite units called tagmata to stay loyal to them during tough times. Only two of these units, the Noumeroi and the Teicheiōtai, stayed permanently in Constantinople, guarding the palace area or other spots in the city.

The city did not keep a very large army because both leaders and people were worried about uprisings and the cost of maintaining many soldiers. Also, the strong city walls provided good protection on their own. Historian John Haldon pointed out that as long as the gates were closed and a small force was in place, the city was safe from large attacks before the use of gunpowder.

Fortifications around Constantinople

Anastasian Wall

Main article: Anastasian Wall

Several strong walls were built near Constantinople to help protect the city. One of the first and most famous was the Anastasian Wall, also called the Long Wall. It was built in the mid-5th century and stretched about 56 kilometers west of the city. Though it was thick and tall, it wasn’t very effective and was abandoned in the 7th century.

Between the Anastasian Wall and the city, there were smaller towns and fortresses like Selymbria and Bakırköy. These places helped protect Constantinople by giving soldiers places to gather and slowing down any attackers.

Walls of Galata

Main article: Galata

Galata, a part of Constantinople near the water, was also protected by walls. By the early 5th century, it was an important part of the city. After Galata was taken over by other groups, they built more walls around their area. Today, only the Galata Tower still stands as a reminder of these old defenses.

Anadolu and Rumeli fortresses

Main articles: Anadoluhisarı and Rumelihisarı

North of Istanbul, two important forts were built to control the Bosphorus waterway. Anadoluhisarı was built by Bayezid I in 1394. Rumelihisarı was built by Sultan Mehmed II in 1452 in just four months. These forts helped the Ottomans control the passage of ships through the Bosphorus. After Constantinople was taken, the forts were used for other purposes until the late 19th century.