On July 22, 838, the rolling plains of Dazimon (in modern-day Turkey) saw one of the most dramatic and consequential battles in Byzantine military history. Known as the Battle of Anzen or Dazimon, this clash pitted the forces of Emperor Theophilos against the Abbasid Caliphate under the Iranian vassal prince Afshin. The aftermath was not just a strategic disaster, but a deep psychological wound that changed the course of the Arab–Byzantine wars and later, the spiritual landscape of Byzantium itself.
Background: Tensions and Triumph
By the early ninth century, the Byzantine Empire and the Abbasid Caliphate had been locked in a brutal, on-and-off conflict for nearly two hundred years. When the young and ambitious Theophilos ascended the imperial throne in 829, he inherited a land under threat but also saw an opportunity to bolster his legitimacy and religious reforms by striking decisive blows against his Muslim rivals.
In 837, Theophilos led a large-scale offensive, reportedly commanding up to 70,000 men, into Abbasid territory, sacking fortified cities such as Arsamosata and Sozopetra (some Byzantine sources claim the latter was Caliph al-Mu’tasim’s birthplace, heightening its symbolic value). Melitene, another key target, was forced to pay tribute and hand over hostages.
Returning to Constantinople as a hero, Theophilos basked in glory and had a commemorative copper Follis minted, depicting his triumph and the proud acclamation, “Theophilos Augustus, you conquer”. But, as history so often runs, success bred hubris and provoked a response of terrible magnitude.
The Abbasid Counterblow: Two Armies, One Goal
Outraged and determined to erase the stain of Byzantine incursions, Caliph al-Mu’tasim gathered a massive force at Tarsus. Some chroniclers place the Abbasid army at up to 80,000, though that number is likely inflated. Still, Mu’tasim’s plan was ambitious and typically Abbasid in both breadth and ruthlessness: he aimed to strike at both Ancyra (Ankara) and Amorion, the latter being not only a strategic hub but the birthplace of the reigning Amorian dynasty—a direct attack on Theophilos’s legacy.
The Abbasid host was divided into two primary armies:
- The northern force, under Afshin (the Iranian prince), invaded from Melitene.
- The southern force, led by the caliph himself, would move through the Cilician Gates and converge on Ancyra.
Crucially, Afshin’s force included a formidable contingent of Turkish horse-archers, a tactical addition that would prove decisive.
Theophilos Prepares: The March to Anzen
Word of the impending invasion reached Theophilos thanks to an extensive network of spies and scouts. He quickly mobilized the empire’s thematic (regional) armies, his elite tagmata, and allied contingents, including Persian and Kurdish Khurramites who had fled religious persecution in the Abbasid lands. These “Persians,” under the converted Theophobos, formed a notable part of the imperial host.
Initially setting up at Dorylaion, Theophilos divided his force:
- One detachment marched to reinforce the garrison at Amorion.
- The main host, somewhere between 25,000 and 40,000 men, moved to head off Afshin in Cappadocia, blocking the route from the Cilician gates to Ancyra.
The Battle of Anzen: Dawn’s Triumph Becomes Dusk’s Disaster
Opening Moves: Byzantine Hope
On July 21, 838, the two armies came within sight of one another near the defensive high ground of Anzen, in the plain of Dazimonitis. The Byzantine command structure was formidable: Theophilos himself, joined by trusted lieutenants Theophobos and Manuel the Armenian.
Despite advice from his principal commanders to launch a surprise night attack, Theophilos opted to wait until dawn. Confidence suffused the imperial camp – the enemy’s numbers were formidable but still inferior, and the Byzantines held the high ground.
At sunrise, the Byzantine host surged forward with the discipline and force for which it was renowned. The initial phase went astonishingly well: one Abbasid wing broke after fierce fighting, with an estimated 3,000 casualties inflicted on the Arabs. The sight of imperial standards advancing must have electrified the troops, as the prospect of a decisive victory against a famed Muslim general seemed within reach.
The Turning Tide: Confusion and Catastrophe
But at this moment of triumph, fate intervened.
Observing the pressure on his other wing, Theophilos decided to personally lead a group of 2,000 elite troops and the Kurdish contingent across his army’s rear to shore up the faltering line. In a highly centralized military system like Byzantium’s, the visible presence of the emperor was critical for morale and command cohesion.
When the regular Byzantine soldiers looked to the rear and saw the imperial standard absent, panic spread. The rumor that the emperor had fallen moved like wildfire through the ranks. Some units lost discipline and began to retreat; in the chaos, some even fled hundreds of miles, carrying tales of imperial death back to Constantinople.
At this juncture, Afshin seized his opportunity. He unleashed his Turkish horse-archers – a relatively new feature in these wars, but one set to alter the fate of both empires. Their hailstorm of arrows both halted the Byzantine advance and shattered the possibility of a controlled withdrawal.
The Collapse: Last Stand at Anzen
Broken, disorganized, the Byzantine army fled. Theophilos, now isolated with his elite tagmata and the Kurdish troops on the hill of Anzen, was surrounded by Abbasid forces. Arrow-fire rained down; it seemed likely the emperor would die or be captured, an event that would have thrown the empire into existential crisis.
At this most desperate moment, a sudden rainstorm swept down on the battlefield. The bowstrings of the Turkish archers were rendered useless. Yet the respite was short-lived; Afshin ordered catapults to be brought up while simultaneous suspicion seeded discord – the Byzantines saw Kurdish troops conversing with the enemy in their own tongue, and feared treachery.
Recognizing the peril, Theophilos and his closest guards fought their way through enemy lines – an epic escape marked by courage and desperation. The remainder of the imperial force left on the hill of Anzen reportedly surrendered. Their fate was lost to history.
Aftermath: The Road to Amorion and Spiritual Upheaval
The retreat from Anzen sent shockwaves across Byzantium. Rumors of the emperor’s death prompted nascent revolts and political intrigue in Constantinople, while Ancyra was abandoned—quickly plundered by the victorious Abbasids on July 27.
The way was now wide open for the Abbasid main army to unite and march on Amorion. After a siege of roughly two weeks, the city fell. More than 35,000 inhabitants were reportedly killed or enslaved. The sack was one of the greatest disasters of the ninth century for the empire, shattering not only military strength but the prestige of the Amorian dynasty itself.
News of domestic revolt forced the Abbasids to withdraw before exploiting their triumph fully, but the psychological and cultural damage was done.
Theophilos himself limped back to the capital, his authority shakier than ever. The Khurramite commander Theophobos briefly attempted to seize power but was eventually persuaded to surrender, and the “Persian” contingent was disbanded.
The Strategic and Tactical Legacy
Byzantium’s Western Lessons
The defeat at Anzen marked a watershed in Byzantine military doctrine. The core of imperial tactics had always relied on discipline, maneuver, and the personal authority of the emperor. But Turkish horse-archers, the forerunners of the mighty Seljuk Turks, represented a new kind of threat, one characterized by rapid mobility, hit-and-run attacks, and excellent skirmishing ability. The loss illuminated the empire’s growing vulnerability to these tactics, and Anzen would be remembered as the beginning of a trend culminating centuries later at Manzikert.
It also marked the first significant encounter between Byzantine armies and the Turkic nomads of the Eurasian steppe, whose descendants would play a key role in Byzantine history.
The End of Iconoclasm
Perhaps surprisingly, the defeat at Anzen had profound spiritual consequences. Theophilos was a resolute iconoclast, and the ideology of iconoclasm – a movement which opposed the veneration of icons – had long justified its stance through claims of military success blessed by God. The defeat at Anzen, followed by the fall of Amorion, severely discredited this doctrine.
Shortly after Theophilos’s death in 842, the iconoclast movement collapsed. The restoration of icons – celebrated as the “Triumph of Orthodoxy” – reinvigorated the empire’s religious unity and remains a point of pride in Eastern Orthodox liturgy to this day.
Conclusion: The Weight of Defeat
The Battle of Anzen stands as a turning point in Byzantine and Middle Eastern history. It encapsulates the perils of overreach, the fragility of command-and-control dependent armies, and the emergence of new military realities that would shape centuries of conflict. The humiliating rout of Theophilos and the subsequent sack of Amorion haunt the Byzantine historical memory – not merely as military defeats, but as triggers of ideological reorientation and change.
For the Abbasids, the victory was brief but brilliant: a demonstration of innovation and tactical flexibility, and a message to the ancient empire of the Mediterranean that its days of unchecked supremacy were well and truly over.
