The 5 Worst Byzantine Defeats

476 is typically regarded as a pivotal year in history, as it saw the “fall of Rome” – the final dissolution of the Roman Empire with the abdication of its last emperor, Romulus Augustulus. Yet, this picture is incomplete, because this applied to the Western Roman Empire only. The Eastern Roman Empire survived for another millennium. Popularly known as the “Byzantine Empire,” it was remarkably resilient in the face of setbacks. And setbacks there were. Unlike the united Roman Empire, its successor never had the same mystique of victory. As a result, its losses are often better-known than its victories. Below are the 5 worst Byzantine defeats.

Worst Byzantine Defeats
One of the Byzantine defeats at the hands of the Bulgars.

5. Siege of Constantinople (1453)

Constantinople had withstood sieges for centuries. Its victory in the sieges of 674-78 and 711-12 proved crucial in keeping Islam out of Europe in the Middle Ages.

It is ironic, then, that the Byzantines themselves invited Islamic warriors into Europe.

This occurred in the 14th century, when future Emperor John VI Cantacuzenus hired the Ottomans as mercenaries for his civil war against his internal enemies. He married his daughter, Theodora, to the Ottoman Emir Orhan to seal this agreement. John’s enemies, in turn, hired their own Turkic mercenaries.

The fact that the Ottomans had previously taken Nicomedia and Nicaea, the Byzantine Empire’s last footholds in Anatolia, didn’t seem to bother them. It was a classic case of short-term tunnel vision, coming at the expense of the long-term interest of the Empire.

The Ottomans established a foothold in Europe after this invitation, ensuring the Empire would witness future defeats. The Siege of Constantinople in 1453 was simply the final, inevitable result of these demographic and military trends. This last humiliation represented a century of failure, the worst and most fatal of late Byzantine defeats.

Siege of Constantinople 1453

4. Battle of Pliska (811)

The 8th century was one of the worst times for the Byzantine Empire. In addition to their losses to the Muslims, they had suffered numerous defeats to the Slavs and Bulgars on their northern border. The worst was yet to come, however.

The new Khan of Bulgaria, Krum, attacked and sacked Sofia in 809, wiping out the whole garrison. To retaliate, Emperor Nicephorus marched on the Bulgarian capital of Pliska, destroying the forces that had been hastily called to oppose him. The capital fell with ease. All was going well. Krum even sued for peace, but Nicephorus refused.

Changing tactics, Krum decided to set up an ambush in the mountains. At the Vărbitsa Pass, the Bulgarians struck the disorganized Byzantines, who had dispersed themselves in their plundering of Pliska and the countryside. Nicephorus only then realized his worst mistake in letting such a thing happen. Reportedly, he said that even if everyone in the army grew wings, they still could not escape ruin.

As at the Teutoburg Wald centuries before, the narrow passes were fortified, making them even more difficult to navigate.

The army was slaughtered. Nicephorus was killed in his camp. As in Germania, only a very few out of tens of thousands escaped. It had been the first time since Adrianople that an emperor met death in battle. Krum reportedly made a cup out of Nicephorus’ skull. Nicephorus’ heir, Staurakios, did escape, but died of his wounds a few months later.

Tactically, this was one of the worst, most lopsided Byzantine defeats.

Battle of Pliska 811

3. Battle of Manzikert (1071)

While one of the Byzantine Empire’s worst defeats, this battle, as I’ve written before, was not the instant catastrophe that is commonly assumed. You can get the full story of this battle in the Critical Battle Series on my Patreon page. Below is the overview.

The Seljuk Turks infiltrated into eastern Anatolia in the middle of the 11th century. Their leader, Alp Arslan, and Emperor Romanus IV Diogenes had earlier agreed to a mutual peace. However, Romanus reneged on the deal. He did not forget earlier Seljuk annexation of Byzantine border fortresses and grew eager to get these back.

As usual for the worst Byzantine defeats, factional intrigue played a part in this disaster. Andronicus Ducas, the son of a rival for the throne, accompanied him on the campaign. This was a critical error. The worst error, though, came in the battle itself, when Romanus put Ducas in charge of the army’s right wing.

For most of the battle, the Byzantines moved forward in good order, with the Seljuks sticking to hit and run tactics. Maintaining a crescent formation, they retreated as the Byzantines advanced.

Romanus ordered a return to camp as the day came to an end, but this became a disordered rout after Ducas spread rumors that the Emperor had been killed. The rear guard retreated and the left flank proved unable to assist the now-surrounded Byzantine right. Romanus himself was captured by the enemy in one of the worst, most humiliating defeats the Byzantine Empire ever suffered.

Though the casualties were relatively low – probably around 8,000 at most, the battle turned into a strategic catastrophe when the Empire again descended into civil war and the Seljuks solidified control of most of Anatolia during the tumult. This robbed the Empire of valuable lands and sources of manpower for its army.

Because of this, Manzikert turned into one of the worst Byzantine defeats.

Battle of Manzikert

2. Sack of Constantinople (1204)

The Crusades, which began as a Byzantine attempt to recover from the defeats at Manzikert and in Anatolia, had mixed results. The initial victories in the First Crusade preceded defeats in subsequent ones. With the Holy Land progressively being cut off, subsequent crusaders turned their energies elsewhere.

The Fourth Crusade initially intended to recapture Jerusalem from the Ayyubid Sultanate, but it was plagued with poor planning. The commanders of the Crusade believed that 33,500 men and 4,500 horses would join the campaign. To transport this force across the sea, the crusaders needed to pay the Venetians (who would do the ferrying) 84,000 silver marks.

Disastrously, only a little over a third of this force actually showed up, and the crusaders were short on money. The Venetians, now deep in the Fourth Crusade, also understood that their honor was on the line, as was their own financial future. They poured many resources into this enterprise. The 80-year-old Venetian Doge, Enrico Dandolo, then made an offer. If the Crusaders captured the port of Zara on the Adriatic, their debts would be forgiven. This they did, to the fury of Pope Innocent III, who was livid that fellow Christians were attacked. He demanded that the crusaders turn their swords back toward the Holy Land, on pain of excommunication. At this point, an exiled Byzantine prince, Alexius, came to their headquarters.

The 21-year-old Alexius promised the crusaders military and monetary support if they would take his side in a dispute against his uncle, Emperor Alexius III. Ignoring Innocent’s instructions, the crusaders agreed. They were now attempting an almost-impossible feat – storming Constantinople.

Dandolo, elderly and nearly blind, proved especially valorous during this part of the Fourth Crusade. The chronicler Geoffery of Villehardouin, a veteran of the action, notes the Doge’s conduct.

The French failed in their own quarter, however, and the crusaders’ initial attack came to nothing. Yet, showing his true character, Alexius III fled. The younger Alexius took the throne as Alexius IV, but could not fulfill the promise he made to the crusaders. He imposed harsh taxes, which included the destruction of religious icons, to raise the necessary money.

Meanwhile, he fell under the influence of an anti-crusader advisor, Alexius Ducas, who usurped power from and executed the unpopular youth, reigning as Alexius V. When Alexius refused to honor his predecessor’s agreement, the crusaders attacked Constantinople again. This time, they did the impossible and sacked it in April, 1204. Alexius V was executed:

There was in Constantinople, towards the middle of the city, a column, one of the highest and the most finely wrought in marble that eye had ever seen; and Mourzuphles [Alexius V] should be taken to the top of that column and made to leap down, in the sight of all the people, because it was fit that an act of justice so notable should be seen of the whole world. So they led the Emperor Mourzuphles to the column, and took him to the top, and all the people in the city ran together to behold the event. Then they cast him down, and he fell from such a height that when he came to the earth he was all shattered and broken.

The city was thoroughly pillaged and vandalized for three days. The crusaders destroyed anything they couldn’t steal, including centuries’ worth of priceless treasures and knowledge.

Afterward, the Byzantine Empire was broken up into several successor states and lost Constantinople. Although the Palaiologos dynasty reunified the Empire and recaptured Constantinople before the end of the century, the sack was an irreversible catastrophe. The Byzantine Empire was irrevocably weakened and left vulnerable to new assailants, this time from the east. Undoubtedly, the Sack of Constantinople in 1204 was one of the Byzantine Empire’s worst defeats. It came, as usual, because of selfish, short-sighted leaders who put their factionalism above the interests of the Empire. Alexius III, IV, and V all fit this description.

Sack of Constantinople 1204

1. Battle of Yarmouk (636)

This was without question the worst of all the Byzantine defeats. You will soon see why.

Islam exploded out of Arabia, only a few short years after the death of the Prophet Muhammad. Byzantine Syria was among the first areas the Muslims attacked. Damascus fell in 634 and the Muslums defeated a Byzantine field army in open battle the next year.

Emperor Heraclius, meanwhile, gathered a huge army to oust the Muslims from Syria. An Armenian general named Vahan commanded by this force. It was about 40,000 strong and outnumbered its enemy by about 2:1.

Ironically, the Byzantine Empire initially sought to ally with its worst enemy, the Sassanid Persian Empire, against their mutual Muslim threat. However, Heraclius deemed the wait time to be too long. He wanted to rid Syria of the Muslim incursion now.

Khalid ibn-al Walid stood in actual, if not nominal, command of the Muslims. He deployed along the Yarmouk River and put his light cavalry on the plains in front, awaiting the Byzantine advance.

The first day’s fighting, on August 15, did not amount to much. Vahan attempted an attack at first light on the following day to achieve surprise. Khalid anticipated this, however, and his scouts informed him of the enemy movements.

The Byzantines attacked anyway and the battle turned into a pushing contest for several days. On day five of the engagement, Vahan asked for a truce, but Khalid refused, knowing now that his opponents’ morale was low. Under cover of darkness, he sent a reserve cavalry force to cut off his enemy’s escape route over a bridge in the rear.

When the next day’s action began in earnest, and the infantry locked horns once again, Khalid personally led a massive cavalry attack against the Byzantine left. The flank collapsed onto the center, while the panicked Byzantine masses were slaughtered in their attempt to retreat, cut off as they were.

It was a total massacre. Almost the entire Byzantine army was destroyed. Meanwhile, the Muslims might have lost a tenth of that number – about 4,000 men. The lopsided tactical disaster alone would have made Yarmouk worthy of being included as one of the worst Byzantine defeats.

Yet, the strategic disaster was of an even greater scale. Yarmouk ensured that the Empire’s wealthiest provinces – Syria, the Levant, and Egypt, were permanently lost to it. Without access to this wealth, the Empire progressively weakened, losing the superpower status that it once had. It was now only another player in the region, constantly attacked from without and embroiled in civil unrest from within.

For this reason, Yarmouk was the worst of all Byzantine defeats.

Battle of Yarmouk

As you saw, bad character was involved in almost all of these catastrophes. To save yourself from your own worst defeats in life, absorb better examples through osmosis by reading Lives of the Luminaries.

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