1. Historical context
On April 5, 838 the Arab al-Mu' tasim (833-842), leading a large military force,1departed from Samarra (where he had transfered the capital of his caliphate abandoning Baghdad) with the intention to invade the Byzantine territories in Asia Minor. The aim of this campaign was the vengeance for the sack of Arsamosata and Sozopetra (Zapetra), the caliph’s birthplace, during a campaign led by the emperor Theophilos the previous year. Contrary to earlier Arab campaigns, which turned against the fortresses on the Arab-Byzantine borders, al-Mu' tasim aimed from the start at the capture of Ankyra and, above all, of Amorion,2 which as the capital of the theme of Anatolikon constituted an important military centre; it was also the cradle of Theophilos’ dynasty, a fact which attached special importance to its possible sacking.3
The caliph camped at Tarsus, by the river Lamos; there he split his troops into two groups. One of these,4under the leadership of the Arab general Afshin (a general of Persian descent), was ordered to join with the troops of the of Melitene ‘Amr al-Aqta' and invade the theme of Armeniakon. Afshin’s contingent marched into the plain of Dazimon, south-east of Amaseia, where it raised camp, while soon after the rest of the Arab forces5 invaded western Cappadocia, the region of general Ashinas (June 19), followed by the main contingent under the caliph two days later. In the meantime, a little earlier (early June) emperor Theophilos, having been informed of the enemy’s movements, left Constantinople to face the Arabs. The emperor’s expeditionary force, which included the under the Manuel, the Persian soldiers of Nasr/Theophobos6 and possibly soldiers drawn from the themes of Thrace and Macedonia, initially camped at Dorylaeum, in order to strengthen the defence of Amorion and Ankyra. The emperor then headed to Cappadocia and camped by the river Halys. Around mid-June, Theophilos was informed that Afshin was in the area of Dazimon. Because the Arab military presence at this particular military junction threatened to cut off of the Byzantines' supply and withdraw routes, Theophilos decided to attack and repel the Arab forces.
2. The battle
On July 21, emperor Theophilos, leading a Byzantine army, reached the plain of Dazimon, where the Arab military force of Afshin, which among others included 10,000 Turkmen mounted archers, had already set up camp. The Byzantines forces took position south of the Dazimon fortress, on a hill called Anzen. Theophilos was in a dilemma about the most approriate time to attack the Arabs. Disregarding the advice of Manuel and Nasr/Theophobos, who argued that they should better move in the night, Theophilos followed the suggestion of the rest of the officers and ordered an attack in the early hours of the following day, July 22. Initially success swung in favour of the Byzantines, who forced a wing of the enemy forces to retreat, inflicting important losses on them (3,000 men). Soon before noon, however, and while Theophilos leading 2,000 men of the tagmata and Nasr/Theophobos’ contingent crossed to the rear of his army to strengthen his other wing, thus being out of sight of the men fighting in the front line, the Arab cavalry launched a ferocious counter-attack. The mounted archers released a rain of arrows on the Byzantine camp, and this fact, combined with Thephilos’ absence from the front line, resulted in the Byzantine troops becoming disarrayed as they were put to a disorderly retreat, abandoning the battlefield. The emperor and his retinue found themselves surrounded on the hill of Anzen, but a storm that suddenly broke out caused the strings of the Arab arrows to loosen, thus removing the immediate danger Theophilos was in. While Afshin was trying to move his stone-hurling war-machines to the first line so as to break the resistance of the last remaining Byzantine troops,7 Theophilos managed to safely retreat from the battlefield8 and sought refuge at Chiliokomon, north of Amaseia. There he regrouped the Byzantine army, as the soldiers who had thought the emperor had lost his life in battle and frightened had scattered in the nearby areas were gradually returning. The victorious Arabs marched towards Ankyra, where they joined the main expeditionary force of the caliph’s invading army a few days later.
3. The consequencesThe defeat of the Byzantine forces by the Arabs in the region of Dazimon, affected negatively the outcome of the Byzantine military operations in Asia Minor in two ways. First, the rumour that spread in Constantinople that Theophilos was killed during the battle gave the opportunity to some officials to pose the issue of proclaiming a new emperor. As soon as Theophilos was informed about this march of events, he was forced to hasten his return to the capital, abandoning his defeated army at a time when the Arabs, encouraged by their victory at Dazimon, continued their military operations in Asia Minor.9 Secondly, the troops of the Persian contingent were reassembled at Sinope or Amastris,10 fearing the emperor’s wrath as they had also taken flight during the battle, and proclaimed Nasr/Thephobos emperor, against his will. Although this insurrection apparently did not have serious consequences for the empire, it did deprive the Byzantine army of a battle-worthy contingent during a crucial turn in the Arab-Byzantine conflict. The Battle of Dazimon is also important for yet another reason: this was the Byzantines’ first contact with the formidable mounted Turkmen archers who in the following centuries will pose a considerable threat to the Byzantine control over Asia Minor, acting either as mercenaries of the caliphate or as independent nomad-raiders and eventually conquerors.11
1. Vasiliev, Α. Α., Byzance et les Arabes Ι: La dynastie d'Amorium (820- 867) (Corpus Bruxellense Historiae Byzantinae I, Bruxelles 1968), p. 146, calculates this force between 200,000 and 500,000 men; on the contrary, Treadgold, W. Τ., The Byzantine Revival 780-842 (Stanford 1988), p. 297, speaks of around 80,000 soldiers accompanied by a multitude of servants, merchants and beasts of burden.
2. It is suggestive that the military standards and the shields of the Arabs had the word ‘Amorion’ engraved on them.
3. Rosser, J., "Theophilus' Khurramite Policy and its Finale: The Revolt of Theophobus' Persian Troops in 838 Βυζαντινά 6 (1974), p. 265, believes that the policy of supporting the Persian rebels adopted by Theophilos was the sole cause of the caliph’s fierce attack against Amorion.
4. According to Treadgold, W. Τ., The Byzantine Revival 780-842 (Stanford 1988), p. 299, it numbered 30,000 and included 10,000 Turkmen and the entire army of Arabian Armenia. Haldon, J. F., The Byzantine Wars (Stroud 2001), p. 80, calculates the numbers of the Arabian force to 20,000 men.
5. According to Treadgold, W. Τ., The Byzantine Revival 780-842 (Stanford 1988), p. 299, they numbered 50,000 men.
6. Nasr took on the name Theophobos after his baptism and by this name he is mentioned in the Byzantine sources. For more see Rekaya, M., "Mise au point sur Théophobe et 1'alliance de Babek avec Théophile (833/834-839/840)", Byzantion 44 (1974), pp. 43-67.
7. Haldon, J. F. The Byzantine Wars (Stroud 2001), p. 82.
8. According to Treadgold, W. Τ., The Byzantine Revival 780-842 (Stanford 1988), p. 300, Manuel was responsible for Theophilos’ rescue: he grabbed the reins of the emperor’s horse and led him away from the battlefield. See also Treadgold, W. Τ., "The Chronological Accuracy of the Chronicle of Symeon the Logothete for the Years 813-845", Dumbarton Oaks Papers 33 (1979), pp. 180-183. On the contrary, Rekaya, M., "Mise au point sur Théophobe et l'alliance de Babek avec Théophile (833/834-839/840)", Byzantion 44 (1974), p. 63, Rosser, J., "Theophilus' Khurramite Policy and its Finale: The Revolt of Theophobus' Persian Troops in 838", Βυζαντινά 6 (1974), p. 269, and Belke, K.- Restle, Μ., Galatien und Lykaonien (Tabula Imperil Byzantini 4, Wien 1984), p. 66, attribute this very action to Nasr/Theophobos, while Vasiliev, Α. Α., Byzance et les Arabes I: La dynastie d'Amorium (820- 867) (Corpus Bruxellense Historiae Byzantinae I, Bruxelles 1968), pp. 156-157, does not suggest which of the two men was the protagonist in this event.
9. Vasiliev, Α. Α., Byzance et les Arabes I: La dynastie d'Amorium (820- 867) (Corpus Bruxellense Historiae Byzantinae I, Bruxelles 1968), p. 158-159, holds that the rebellion of the Persian troops and Nasr/Theophobos’ proclamation as emperor forced Theophilos’ to hasten his return to Constantinople. On the contrary, Treadgold, W. Τ., The Byzantine Revival 780-842 (Stanford 1988), p. 301-302, Belke, Κ., Paphlagonien und Honorias (Tabula Imperil Byzantini 9, Wien 1996), p. 75, and Cheynet, J.-Cl., "Théophile, Théophobe et les Perses", in Λαμπάκης, Σ. (ed.), Η Βυζαντινή Μικρά Ασία (6ος-12ος αιώνας) (Διεθνή Συμπόσια 6, Αθήνα 1998), pp. 44-45, do not correlate the two events, but attribute the emperor’s return to the capital to the machinations of certain nobles aimed at proclaiming a new emperor. According to Rosser, J., "Theophilus' Khurramite Policy and its Finale: The Revolt of Theophobus' Persian Troops in 838", Βυζαντινά 6 (1974), p. 269, it is very likely that they wished to proclaim Nasr/Theophobos emperor.
10. This second version is mentioned by Vasiliev, Α. Α., Byzance et les Arabes I: La dynastie d'Amorium (820- 867) (Corpus Bruxellense Historiae Byzantinae I, Bruxelles 1968), p. 159, and Cheynet, J.-CL, "Théophile, Théophobe et les Perses", in Λαμπάκης, Σ. (ed.), Η Βυζαντινή Μικρά Ασία (6ος-12ος αιώνας) (Διεθνή Συμπόσια 6, Αθήνα 1998), p. 44.
11. Kaegi, W. Ε., "The Contribution of Archery to the Turkish Conquest of Anatolia", Speculum 39 (1964), pp. 96-108.