The Sack of Thessaloniki in 904

By Anne Thériault

Early tenth-century Thessaloniki was a jewel in the crown of the Byzantine Empire, second in greatness only to Constantinople itself. A cosmopolitan city that boasted a deep natural harbour and was surrounded by fertile agricultural lands, it was rich both in resources and culture. Years of peace and prosperity meant that the people of Thessaloniki had become used to a high quality of life. It also meant that they had grown lax in their defence of the city, a fact that would be driven home to them to a dramatic degree by the events of AD 904.

It was in the summer of that year that a messenger from the Byzantine emperor Leo VI rushed into town with terrible news: Leo of Tripoli was on his way to attack Thessaloniki. Leo of Tripoli came from Greek origins, but he had been captured in an Arab raid when he was young, converted to Islam, and began working for his captors. He had sailed from Syria with a fleet of 54 ships with the intention of freeing a group of some 4,000 Muslims being kept prisoner there, as well as sacking and looting the city.


Much of our understanding of what happened during the Sack of Thessaloniki comes from one man: John Kaminiates. John came from a wealthy Thessalonian family and was taken prisoner by Leo of Tripoli’s forces. He later wrote a first-hand account of it in a letter addressed to a man named Gregory of Kappadokia. His unsparing descriptions of the violence and brutality inflicted on the residents of Thessaloniki provides us with a rich source of information about the attack.

According to Kaminiates, the city’s fortifications on land were strong. The wall around the city, complete with battlements and towers, was well made and had been kept in good repair. However, the city was vulnerable from the south, through its harbour. Unlike the wall, the fortifications in the water had been hastily built centuries before during a conflict with the Persians and hadn’t been improved since. Apparently no one had worried too much about this, since up until then all of their conflicts had been on land. It was only once those in charge of the city received word that Leo and his men were coming by sea that they realized how vulnerable they were from that angle.


The messenger who had come from the emperor, a man named Petronas, had also been instructed to help shore up the city’s defences. He came up with an ingenious plan to use stones from old pagan tombs to build a sort of underwater fence that would be invisible from above but would tear out the hulls of approaching ships. But work on this fence was only partway completed when yet another envoy came from the emperor to take Petronas’ place. He decided that the underwater fence was a bad idea and that instead the city should turn their attention to building up the weak sea wall.

This plan might have worked if they’d had time to complete it, but soon after the second envoy’s arrival yet another messenger, named Niketas, arrived with the news that Leo and his ships were only a few days’ sailing away. To make matters even worse, when the second envoy went to greet Niketas, the horses took fright and the envoy was thrown, badly injuring himself in the fall. This meant that the strategic brain behind Thessaloniki’s defence was out of commission just when he was needed most.

The Thessalonians spent the next several days panicking, praying, and continuing to work fruitlessly on the sea wall. Then, on July 29, Leo of Tripoli’s ships were spotted just off the city’s jetty, looking, according to Kaminiates, as if they were not “gliding over the surface of the water but floating through the air”. This surreal vision ended with the ships dropping anchor in the harbour for several hours while Leo and his men surveyed the city’s defences and plotted out how best to attack. On land, the Thessalonians could only wait for the inevitable.

the sack of Thessaloniki in 904, depicted in the Madrid Skylitzes, fol. 111

A city falls

Then, all of a sudden, Leo of Tripoli apparently gave the sign for battle and his ships “swooped in”, his men drumming and screaming as they approached the wall. In spite of Leo’s forces having several advantages – the element of surprise, the fact that they were all seasoned fighters, the vulnerability of the defences – for a while it almost seemed like the Thessalonians might hold their city. Even when the invaders jumped into the water and swam up to the wall with wooden ladders, the Thessalonians managed to repel them by dropping rocks on them. Niketas, the last messenger who had arrived from the emperor, was impressed, admitting that he hadn’t expected the city’s inhabitants to be so brave.


That night, Leo of Tripoli’s forces retreated back to their ships. In the morning, the invaders tried a new tactic: they placed carts stacked with wooden boats, brushwood, and anything else that might be flammable in front of the city’s outer gates. After drenching them with pitch and sulphur, they set them on fire. The heat was so intense that the gates, which were iron-plated, caught flame and collapsed. As the Thessalonians rushed to defend the inner gates, the invaders returned to their ships to prepare for their most powerful manoeuvre yet.

Under Leo of Tripoli’s supervision, his men lashed the ships together and then tied the huge steering paddles to the masts, bracing them with strips of wood. The most elite among the invaders climbed up onto these contraptions, which turned the ships into floating siege towers. By this point the Thessalonians had returned to the seat wall and watched in helpless horror as the ships crashed into the wall. As the crowd retreated, the invaders began spilling into the city. Chaos and bloodshed quickly ensued.

Leo of Tripoli’s men began killing everyone in sight – men, women, children. Some Thessalonians tried to flee through one of the gates, but the swell of the crowd slammed it shut. As this was happening, the invaders began decapitating and mutilating those trying to escape. The crowd continued to try to push through the dead bodies to get out the gate, while Leo of Tripoli’s forces beheaded wave after wave of people. The same thing then happened at another of the city’s gates. There was no escape.


A life saved

Kaminiates, along with his father, brothers, and uncle, witnessed all of that and retreated to a nearby tower to try to strategize. The invaders soon found them, but the floor of the tower was made up of rotting planks, which made them pause in their advance. Instead of fleeing further into the city, Kaminiates, who knew a safe path across the tower, approached the invaders directly, telling them that if they spared his family’s life, he would take them to their hidden stash of treasure.

The invaders brought Kaminiates and his family to a nunnery, where they found Leo of Tripoli sitting cross-legged on the altar. He agreed to spare their life in exchange for their money and valuables. Then, as Kaminiates and his family watched in horror, he slaughtered all the other Thessalonians who were being kept in the nunnery. The floor of the church was so choked with bodies that the invaders had to stack them along the walls just so that they could leave. Kaminiates said that he and his father and brother could only look at each other with blank expressions; the brutality was more than they could process.

The invaders told Kaminiates that if he was lying about his family’s treasure, they would hack him to pieces just as they had the people in the nunnery. He led them to where his valuables were hidden and, fortunately for him, they determined that they were enough to buy his family’s survival. However, that wasn’t the end of their suffering – far from it. Even though the invaders weren’t going to kill Kaminiates, they were going to take his entire family hostage to use in a prisoner exchange.

Kaminiates and his family were brought to an enclosure by the water where the rest of the captured Thessalonians were being kept. Everyone was in a state of heightened terror, made worse by the fact that they weren’t allowed to sleep: the invaders stayed up all night yelling and making noise. The hostages also weren’t given any food or water; eventually the invaders allowed them to drink from a nearby sewage channel, the stomach-turning liquid of which seemed like “a sweet, pure draught of newly-melted snow” to the extremely dehydrated prisoners.


The hostages were kept under these conditions for ten days while the invaders pillaged the city. They were all people who, like Kaminiates, had promised to deliver family treasure, and one by one they were brought to their dwellings to make good on these promises. Anyone found to be lying or exaggerating was immediately executed.

A prisoner on the sea

Finally, on the tenth day, the prisoners were loaded onto the ships. Families were split up, children separated from their parents. Kaminiates did not know if his wife or children were alive or dead; if they hadn’t been killed during the invasion, then they must have been held in a separate area during the ten-day sack of the city. The only small mercy was that he and his father, brothers, and uncle were put on the same ship. But there the mercies ended: on board the ship, the prisoners were shackled and stacked like cargo. All through that first night Kaminiates could hear weeping and screaming around him as his fellow prisoners begged for food and called out to God.

On the ship, the prisoners continued to be given polluted water to drink; the only food they were given was rotten bread. Conditions were awful, with people being forced to relieve themselves wherever they were chained, often on another person. Lice were unsurprisingly rampant. People began dying in droves, and their bodies were just tossed overboard.

The ship pulled into port at Naxos, where the prisoners were given fresh water for the first time and, eventually, allowed to disembark. For the first time, Kaminiates truly understood the scope of what was happening: Leo of Tripoli had taken 22,000 of his fellow Thessalonians prisoner. He had killed countless more.

The prisoners’ arrival at Naxos was a bittersweet moment: families were reunited and parents could finally embrace their children again, but it was also the moment when many of them learned of the deaths of their loved ones at sea. Kaminiates himself learned that his wife and two older children had survived, although tragically their youngest had died on board the ship. His brother wasn’t so lucky; his wife had survived, but instead of being used as a hostage in the prisoner exchange, she was going to be sold into slavery on Crete.

As if that wasn’t bad enough, Leo of Tripoli’s men, having briefly allowed the families to be together, now separated them again and forced them to re-board the ships. This time they were sorted based on their physical traits, with the older ones being put into the hostage groups and the youngest and most physically attractive people being sold, like Kaminiates’ sister-in-law, into slavery.

Shortly after the ships re-launched there was a terrible storm. One of the ships was split nearly in two by the violent winds and waves, and the sailors on board begged Leo of Tripoli, who was on his own craft, to throw all the prisoners from Kaminiates’ ship into the sea so that they could take their places and be saved; their lives, they argued, mattered more than those of the hostages. Leo of Tripoli agreed to do as they asked, and Kaminiates was sure that death had come for him at last.

But at the last moment, the gale blew Kaminiates’ ship out of reach and he was saved. The sailors on the sinking ship then begged Leo of Tripoli to empty his own ship of treasure so that they could be saved and – no doubt thinking of how valuable the prisoners on the foundering vessel were – he agreed to take everyone on board. The transfer had barely been completed when the injured ship sank beneath the waves; Kaminiates, a very religious man, believed that it had been an act of Providence that had saved the Thessalonians on the other ship.

On September 14, the fleet of ships arrived in Tripoli. Kaminiates and his fellow hostages were humiliated by being paraded triumphantly through the streets by their captors, but at least their living conditions there were much better than they had been. It was there, before being sent off to Tarsos for the prisoner exchange, that Kaminiates met Gregory of Kappadokia and promised to send him an account of everything he’d endured. It was also in Tripoli that Kaminiates’ father died, having been weakened by the gruelling journey from home.

The letter concludes with Kaminiates continuing to wait to be sent to Tarsos. He expresses his worries that he and his family will die before they’re granted their freedom, just as his father had. Will he ever see Thessaloniki again? And if he does, will it at all resemble the beloved home he remembers?

The Sack of Thessaloniki is barely a ripple in the waters of conflict during the medieval period. There are plenty of other events that were bigger, more violent, or more world-changing. But Kaminiates’ account shows the gutting civilian cost of raids and warfare. The smaller details that he shares are what really bring home the horror of it all: details such as his father’s breakdown before they’re even captured, during which he weeps about the unnaturalness of being a parent faced with your children’s death, or the women screaming and tearing their own clothes with grief as they learn of their babies lost at sea, or even the haunting moment when the prisoners are grateful that their captors are allowing them to drink literal sewage.

When it comes to talking about war, we’re good at looking at the large-scale human costs, such as the number of lives lost, but the smaller, equally disquieting tragedies tend to get lost in the mix. Writings like those of John Kaminiates are important not just because they provide crucial first-person accounts of historical events, but also because they bring into focus the experiences of the people we might consider fortunate for surviving events like these yet who still have their lives completely derailed as a result.

Anne Thériault is a Canadian writer and historian. You can follow her on Twitter @anne_theriault.

Further Readings:

The Capture of Thessaloniki, by John Kaminiates, translated by David Frendo and Athanasios Fotiou in the year 2000. Their translation is part of the Byzantina Australiensia series, produced by the Australian Association for Byzantine Studies.

This article was first published in Medieval Warfare magazine. Check out the issues of that magazine here.