A Desperate Emperor and a Fearsome Army
Our story begins in 1302 with a fading power: the Byzantine Empire. Still reeling from the Fourth Crusade a century earlier, the empire was a shadow of its former self. Emperor Andronikos II Palaiologos watched helplessly as Turkish emirates consumed his territories in Anatolia (modern-day Turkey). His armies were ineffective, his treasury was bare, and his situation was desperate.
Into this scene of imperial decay stepped Roger de Flor. A man of ambition and questionable morals—a former Knight Templar excommunicated for allegedly absconding with Templar funds during the Siege of Acre—Roger was the charismatic leader of the Catalan Company. This was no ordinary band of mercenaries. His men were the Almogavars, rugged mountain-men and veterans of the brutal War of the Sicilian Vespers.
The Almogavars were a terrifying sight on the battlefield. Lightly armored in leather and mail, they were incredibly mobile and fought with a primal ferocity. Armed with a long knife (coltell), a short sword, and a handful of heavy javelins (azconas), their signature tactic was to hurl their javelins to shatter enemy shields and break formations before charging in on foot to finish the job. Their blood-curdling battle cry, “Desperta ferro!”—Catalan for “Awaken, iron!”—was a sound that heralded slaughter, as they struck their weapons against flint to create a shower of sparks before a charge.
Success, Arrogance, and Betrayal
In September 1303, Roger de Flor and his 6,500-strong Catalan Company arrived in Constantinople. The Emperor made Roger a Grand Duke (Megas Doux), married him to a princess, and promised him mountains of gold. The Catalans were an immediate and startling success. They were ferried across to Anatolia and, in a series of lightning campaigns, smashed the Turkish forces, routing them in battles like the Battle of the Cyssus and pushing them back from the coast.
But their success bred arrogance and friction. The Catalans were boisterous, demanding, and utterly ruthless, not just to their enemies but also to the Byzantine locals they were supposed to be protecting. They saw the Byzantines as soft and duplicitous, while the imperial court saw the Company as a band of uncouth, dangerous barbarians—a force more threatening than the Turks they were hired to fight.
The breaking point came in 1305. Fearful of Roger de Flor’s growing power and ambition, the co-emperor Michael IX Palaiologos lured him and his officers to a banquet in Adrianople. During the feast, assassins burst in and murdered Roger and his entourage. A coordinated massacre of Catalans across the empire followed. The Byzantines believed they had decapitated the beast.
They were wrong. They had only made it rage.
The Catalan Vengeance
Receiving news of their leader’s assassination, the remaining Catalans didn’t flee or surrender. United by grief and a thirst for retribution, they declared war on the Byzantine Empire. This bloody chapter of their history is known as the “Catalan Vengeance.”
For two years, the Company carved a path of destruction through the Byzantine territories of Thrace and Macedonia. They were no longer an army for hire; they were a force of nature. They burned villages, sacked towns, and slaughtered anyone who stood in their way. The Byzantine chroniclers of the time wrote with horror of the devastation they left behind, creating a black legend that would echo for centuries. Having thoroughly savaged the empire, the Company moved south, looking for new employment and new plunder.
A Fateful Contract in Athens
By 1310, the wandering Company arrived in a Greece fragmented into a patchwork of small states ruled by French and Italian nobles—a legacy of the Fourth Crusade. Here, they found a new employer: Walter V of Brienne, the French Duke of Athens. He hired the fearsome mercenaries to help him assert his authority over the neighboring Greek lords of Thessaly.
Once again, the Catalans proved their devastating effectiveness, swiftly conquering over 30 castles for Duke Walter. And once again, history repeated itself. When the campaign was over, Walter made the same fatal mistake as the Byzantines. He declared their contract complete, paid them for only two months of their service, and ordered them to leave his duchy. He offered to retain just 500 of the best men for his personal service, dismissing the rest. The Catalans, feeling cheated and disrespected, refused to go.
The Battle of Halmyros: Conquest of a Duchy
What followed was one of the most decisive and remarkable battles of the Middle Ages. On March 15, 1311, on the plains of Boeotia near the Cephissus River (also known as the Battle of Halmyros), the Catalan Company faced the might of Frankish Greece.
Duke Walter had assembled a formidable army of knights from across the Latin states, including 700 heavily armored cavalry—the flower of French chivalry. The Catalans, outnumbered and on foot, used their cunning. They diverted the nearby river to flood the plain in front of their position, turning the solid ground into a muddy, hidden marsh, covered by a thin layer of turf.
Blinded by arrogance, the Frankish knights charged headlong at the Catalan line. Their powerful warhorses plunged into the unexpected bog, stumbling and trapping their heavily armored riders in the mud. Stuck, helpless, and immobile, they were easy prey for the lightly-equipped Almogavars, who swarmed over them in a brutal slaughter. Duke Walter and almost his entire nobility were killed. At the end of the day, the Catalan Company had not just defeated an army; they had annihilated the ruling class of an entire duchy.
With no one left to oppose them, the Catalans marched into Athens and Thebes and took the duchy for themselves. The mercenaries had become masters.
A State Run by Soldiers
The Catalan Duchy of Athens was a unique political entity in European history—a state founded and run by a corporation of soldiers. The common troopers became feudal lords overnight, taking the castles, lands, and widows of the knights they had slain. They established a council of leaders and, seeking legitimacy, offered nominal sovereignty to the King of Sicily, a branch of the Crown of Aragon.
For the next 77 years, the Acropolis of Athens flew the banner of Aragon. Catalan, not French or Greek, became the official language of government. The laws of the land were replaced by the Constitutions of Catalonia. Though their rule was often marked by internal squabbles and piracy, it was remarkably stable. They had achieved what no mercenary company had ever done before: they had conquered their own state and held it for generations.
Their grip on Athens finally ended in 1388, when they were displaced by the rival Navarrese Company and then conquered by the powerful Florentine Acciaioli family. Yet, the legacy of the Catalan Company remains—a stunning testament to ambition, betrayal, and brutal survival. They were hired swords who, through vengeance and astonishing military prowess, transformed themselves from mercenaries into the rulers of one of history’s most celebrated cities.