Everybody knows about the Walls of Constantinople, often called the mightiest fortifications of the pre-gunpowder age. Famously, the walls saved the city, and thus the Byzantine Empire, from a thousand years of invasions by Persians, Avars, Bulgars, and Arabs before falling before the Ottomans in 1453. Today, tourists in Istanbul take photo-ops by the partly-reconstructed walls, even as architects admire the ingenious engineering.

Ever since the climactic fall of the city, the walls have passed into legend. J.R.R Tolkien himself took inspiration from Byzantium in describing the mighty fortifications of Minas Tirith, with the city’s “archway that no enemy ever yet had passed.”

As the popular story goes, the only thing that could break the mighty defenses were hordes of Muslim invaders, who used cannon and waves of expendable troops to overwhelm the heroic defenders and extinguish the last remnant of the Roman Empire. 

The Reality

The only problem is that none of this is true. While the Byzantine walls did throw back several a number of invading armies (most notably several Arab assaults during the 7th and 8th centuries), their record is far from spotless. For every failed siege, there were one or more successful attacks on the supposedly impregnable city.

However, commentators use a highly selective list of attacks on Constantinople. Most importantly, most descriptions of the city’s defenses completely ignore the Byzantine civil wars. Rival claimants battling for control was a common feature of Byzantine politics, and the struggles often involved seizing Constantinople by military force. During the reign of Emperor John V, for example, the city fell to outside attackers no fewer than six times, in 1347, 1354, 1376, 1379, and twice in 1390. 

Admittedly, these were not sieges like you’d see in The Lord of the Rings. Typically, claimant attacking the city would besiege the walls for only a matter of days or weeks before sneaking in through a bricked-up gate or a door left conveniently open. By the 14th century, the city walls had become a sieve of secret entrances and unguarded gates. 

Yet even in the prime years of the wall, Constantinople proved almost comically vulnerable to attack. Within a few years of the famous Arab sieges, the Byzantines endured the Twenty Year Anarchy (695-717) in which no fewer than seven emperors seized power in quick succession. Three of these rulers took the throne through a successful assault on Constantinople. Take Justinian II, also known as Justinian No-Nose, who besieged the city in 705 with a large army of Bulgar and Slav allies. After his initial attacks failed, Justinian discovered a secret sewer running into the city. He snuck in at night with his men, and the city fell within hours. 

The city walls were also vulnerable to direct assault, even before advent of gunpowder. In 1204, a crusading army conquered the city through sheer brute force, despite a determined resistance. Some historians might protest that the Crusader attack broke through the seawalls, thus preserving the reputation of the landward Theodosian Walls, but at that point we’re splitting hairs. 

An objective examination reveals that Constantinople’s defenses had a record that was, at best, mixed. The walls repelled Arabs, Avars, and Bulgars, but proved easy for countless Byzantine claimants to circumvent. The fortifications also could not stop the armies of the 4th Crusade. In the end, it was civil war and crusaders who destroyed the city, far more than the Ottomans. The Constantinople that fell to Mehmed the Conquerer in 1453 was already a shadow of its former glory, with a population of only 50,000, down from a high of more than half a million.

So why does popular history sweep the many, many successful assaults on Constantinople under the rug? Part of the reason may be the dramatic appeal of the traditional myth. People have a deep attachment to the idea (reinforced by Tolkien and others) of Constantinople as an unconquerable bastion of civilization, perpetually besieged by the hordes of darkness.

However, we must also appreciate that our myth is based in an unfair and inaccurate perception of the city’s Muslim attackers. The Ottomans were, we must recall, among the most technologically sophisticated civilizations of their day, and, according to some historians, treated the conquered city less brutally than the crusaders had in 1204. 

Compared with the popular account, the repeated seizure of the city by “friendly” forces (although I doubt anyone in the city considered the crusaders an ally) don’t really fit. It’s like Dwarves laying siege to Minas Tirith. “But they’re also the good guys!” Perhaps its no wonder that people prefer to stick to the old, more convenient story of Constantinople as an eternal, untainted bulwark. 

Yet I would argue that the many falls of Constantinople make for a more interesting story. The city’s vulnerability reminds us that even the most defensible fortifications are useless when you can’t trust the guys with the keys.