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  • Writer's pictureHarry Prance, MA

A Brief History of the Walls of Constantinople in Istanbul

What are the Walls of Constantinople?

The Walls of Constantinople are 5th-century walls that symbolise the longevity of the Byzantine Empire.

Walls of Constantinople

Walls of Constantinople History

Protected by the sea on three sides, the Late Antique city of Constantinople was vulnerable to attack primarily from its western landward flank. However, these restored walls which you see before you were not the first defensive structures to protect the city. Constantine had built walls when he founded it, but the population of the capital had expanded significantly over the decades as its position as the new centre of the empire became established and many inhabitants lived outside the original walls. The sack of Rome in AD 410 by the Visigoths was not only a nail in the coffin of the Western Empire but a wake-up call to the East – if Constantinople were to avoid the same fate, the city would have to be impregnable.

The new walls were completed in AD 413, under the direction of the prefect of the city, Anthemius. The original structure was just a traditional curtain wall with defensive towers; however, these were severely damaged by two separate earthquakes in the 5th century. With Attila the Hun raiding the Balkans, Theodosius II ordered the prefect Constantine to repair the damage and, using the collective labour of the citizens, the defences were reconstructed, according to historians and inscriptions on the walls themselves, in an astounding 60 days. It’s thought that this is when they developed their distinctive double fortification: a very high inner wall, encircled by a lower outer wall and beyond that a moat. Today, the walls stretch for nearly six kilometres. Originally, they would have extended to the Golden Horn, but are now lost beneath the sprawl of the contemporary city. The walls are massive; it’s no wonder they defeated siege engine after siege engine. The two lines of defence are separated by a broad terrace – the inner wall is 13 metres above ground in some places and 4.5 metres thick with a solid core of mortared rubble, while the outer wall is 9 metres tall and 2 metres thick.

The walls repelled attacks by almost every enemy of the Byzantine Empire, but the most persistent threat came in fact from the earthquakes that regularly rock the city. As the empire declined and its former riches were unavailable to the later rulers of Constantinople, fewer and fewer resources were allocated to the upkeep of the city walls. By the time of the Ottoman conquest in 1453, the Theodosian Walls were not the impregnable defence they had once been, though even then and despite repeated bombardment by cannon fire, the skeleton Genoese garrison on the walls kept the Ottomans at bay for two months. When the Ottomans finally breached the city walls on the 29th of May 1453, they were the first conquerors to do so in a millennium.

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