Treaty of Devol

From Academic Kids

The Treaty of Devol was an agreement made in 1108 between Bohemund I of Antioch and Byzantine Emperor Alexius I, in the wake of the First Crusade. Although it was not initially enforced, it was intended to make the Principality of Antioch a vassal state of the Byzantine Empire. It is a typical example of the Byzantine tendency to settle disputes through diplomacy rather than warfare, and was both a result of and a cause for the distrust between the Byzantines and their Western European neighbors.



Byzantine emperor Alexius I Comnenus
Byzantine emperor Alexius I Comnenus

In 1096, the Crusader armies assembled at Constantinople after having traveled separately eastward through Europe. Alexius I, who had requested only mercenaries from the West to help fight the Seljuk Turks, blockaded these armies in the city and would not permit them to leave until their leaders swore oaths promising to return to the Empire any land that they might conquer on the way to Jerusalem. The Crusaders eventually swore these oaths, individually rather than as a group; some, such as Raymond IV of Toulouse, were probably sincere, but others, such as Bohemund, probably never intended to honor their promise. It was generally understood by the Crusaders that Alexius would, in return, offer Byzantine military assistance. Alexius was indeed prepared to do so, although the Crusaders were exasperated by Byzantine tactics, such as negotiating the surrender of Nicaea from the Seljuks while it was still under siege by the Crusaders, who hoped to plunder it to help finance their journey. The Crusaders, feeling betrayed by Alexius, continued on their way without Byzantine aid. In 1098, when Antioch had been captured after a long siege and the Crusaders were in turn themselves besieged in the city, Alexius marched out to meet them, but, hearing from various deserters that the situation was hopeless, he returned to Constantinople. The Crusaders, who had unexpectedly withstood the siege, believed Alexius had abandoned them and now considered the Byzantines completely untrustworthy.

By 1100, there were several Crusader states, including the Principality of Antioch, founded by Bohemund in 1098. It was argued that Antioch should be returned to the Byzantines, despite Alexius's supposed betrayals, but Bohemund disagreed and claimed it for himself. Alexius, of course, disagreed; Antioch had an important port, was a trade hub with Asia, and was a stronghold of the Eastern Orthodox Church, with an important Greek Patriarch. It had only been captured from the empire a few decades previously, unlike Jerusalem, which was much farther away and had not been in Byzantine hands for centuries. Alexius, therefore, did not recognize the legitimacy of the Principality, believing it should be returned to the Empire according to the oaths Bohemund had sworn in 1097.

In 1100, Bohemund added a further insult to Alexius and the Orthodox Church by appointing Bernard of Valence as the new Latin Patriarch, at the same time expelling the Greek Patriarch, John the Oxite, who fled to Constantinople. Soon after this, Bohemund was captured by the Danishmends of Syria and was imprisoned for three years, during which the Antiochenes chose his nephew Tancred as regent. After Bohemund was released, he was defeated by the Seljuks at the Battle of Harran in 1104; this defeat led to renewed pressure on Antioch from both the Seljuks and the Byzantines. Bohemund left Tancred in control of Antioch and returned home, touring Italy and France to raise more troops and money for a new crusade.

Bohemund's Norman relatives in Sicily had been in conflict with the Byzantine Empire for over 30 years; his father Robert Guiscard was one of the Empire's strongest enemies. While Bohemund was away Alexius sent an army to reoccupy Antioch and the cities of Cilicia. In 1107, having organized a new army for his planned crusade against the Muslims in Syria, Bohemund instead launched into open warfare against Alexius, crossing the Adriatic to besiege Dyrrhachium, the westernmost city of the Empire. Like his father, however, Bohemund was unable to make any significant advances into the Empire; Alexius avoided a pitched battle and Bohemund's siege failed, partly due to a plague among his army.


In September 1108, Alexius requested that Bohemund negotiate with him at the imperial camp at Diabolis (Devol). Bohemund had no choice but to accept, now that his disease-stricken army would no longer be able to defeat Alexius in battle. He admitted that he had violated the oath sworn in 1097, but refused to acknowledge that it had any bearing on the present circumstances, as Alexius, in Bohemund's eyes, had also violated the agreement by turning back from the siege of Antioch in 1098. Alexius agreed to consider the oaths of 1097 invalid. The specific terms of the treaty were negotiated by the general Nicephorus Bryennius, and were recorded by Nicephorus' wife, Alexius' daughter Anna Comnena:

  • Bohemund agreed to become a vassal of the emperor, and also of Alexius' son and heir John;
  • He agreed to help defend the empire, wherever and whenever he was required to do so, and agreed to an annual payment of 200 talents in return for this service;
  • He was given the title of sebastos, as well as doux (duke) of Antioch;
  • He was granted as imperial fiefs Antioch and Aleppo (the latter of which neither the Crusaders nor the Byzantines controlled, but it was understood that Bohemund should try to conquer it);
  • He agreed to return Laodicea and other Cilician territories to Alexius;
  • He agreed to let Alexius appoint a Greek patriarch.

A Byzantine title and a grant of land may have been all Bohemund was looking for in the first place in 1097, although he may have also wanted the title of Grand Domestic of the East, rather than simply sebastos.

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The terms were negotiated according to Bohemund's western understanding, so that he saw himself as a feudal vassal of Alexius, a "liege man," homo ligius or ανθροπος λιζιος. However, in Byzantine terms he was essentially a conquered enemy drafted into mercenary service for the empire, as evidenced by the annual payment. The title of doux meant that he was a Byzantine subject, not an independent prince (the title he had given himself in 1098); this was more similar to the Byzantine pronoia system than to the western feudal system.

In any case, Antioch was granted to Bohemund for life, unless the emperor (either Alexius or, in the future, John) chose for any reason to renege on the deal. The principality would then revert to direct Byzantine rule on Bohemund's death. Bohemund therefore could not set up a dynasty in Antioch, although Alexius promised him a hereditary dukedom elsewhere (possibly the County of Edessa; there is text missing in the Alexiad, but if this is the case, neither Bohemund nor Alexius controlled that territory either, although at the time Tancred was regent there as well as in Antioch).

Anna Comnena described the proceedings with very repetitive details, with Bohemund frequently pointing out his own mistakes and praising the benevolence of Alexius and the Empire. The treaty appears to be entirely to Alexius' benefit, and the proceedings must have been rather humiliating for Bohemund. On the other hand, Anna's work was meant to praise her father and the terms of the treaty may not be entirely accurate. It is notable that Crusader sources either mention the treaty only in passing, or do not mention it at all.

The treaty was concluded with an oath sworn by Bohemund, as recorded by Anna:

"...I swear to you, our Lord and Emperor Alexius Comnenus, most powerful and revered, and to your co-Emperor, the thrice-beloved Lord John the Porphyrogenitus, that all the agreements made between us and confirmed by me verbally I will observe and will for ever keep absolutely inviolate...In thought and in deed I shall do everything to help and honour the Empire of the Romans..."

The oral agreement was written down in two copies, one given to Alexius, and the other given to Bohemund. According to Anna, the witnesses from Bohemund's camp who signed his copy of the treaty were Maurus, bishop of Amalfi and papal legate, Renard, bishop of Tarentum, and the minor clergy accompanying them; the abbot of the monastery of St. Andrew in Brindisi, along with two of his monks; and a number of unnamed "pilgrims" (probably soldiers in Bohemund's army). From Alexius' imperial court, the treaty was witnessed by the sebastos Marinus, Roger son of Dagobert, Peter Aliphas, William of Gand, Richard of the Principate, Geoffrey of Mailli, Hubert son of Raoul, Paul the Roman, the ambassadors Peres and Simon from Hungary, and the ambassadors Basil the Eunuch and Constantine. Interestingly, many of Alexius' witnesses were themselves westerners, and Basil and Constantine were ambassadors in the service of Bohemund's relatives in Sicily.

Neither copy of the treaty survives. It is unknown if it was written in Latin, Greek, or both. Both languages are likely given the number of westerners present, many of whom would have known Latin.


Bohemund then returned to Sicily and died in 1111, before he had an opportunity to return to Antioch; or, perhaps, he felt he had lost his prestige and power there and did not want (or dare) to return. He probably realized his nephew Tancred would be persuaded to honour the treaty only by force of arms; in Bohemund's absence, Tancred indeed refused to honour it. In his mind, Antioch was his by right of conquest. He saw no reason to hand it over to someone who had not been involved in the Crusade, and had indeed actively worked against it (as the Crusaders believed). The Crusaders seem to have felt Alexius had tricked Bohemund into giving him Antioch; they already believed Alexius was devious and untrustworthy and this may have confirmed their beliefs. The treaty referred to Tancred as the illegal holder of Antioch, and Alexius had expected Bohemund to expel him or somehow control him. Tancred also did not allow a Greek Patriarch to enter the city; instead, Greek Patriarchs were appointed in Constantinople and nominally held power there.

The question of the status of Antioch and the adjacent Cilician cities troubled the Empire for many years afterwards. The Treaty of Devol seems to have been considered void after Bohemund's death, but Alexius' son John attempted to impose his authority in Antioch, travelling to Antioch himself in 1137 to negotiate a new treaty. In 1138 a riot was engineered against him and he was forced to leave. It was not until 1158, during the reign of Manuel I Comnenus, that Antioch truly became a vassal of the empire, after Manuel forced Prince Raynald of Chatillon to swear fealty to him in punishment for Raynald's attack on Byzantine Cyprus. The Greek Patriarch was restored, and ruled simultaneously with the Latin Patriarch. Antioch, weakened by powerless regents after Raynald's capture by the Muslims in 1160, remained a Byzantine vassal state until 1182 when internal divisions following Manuel's death in 1180 hindered the Empire's ability to enforce its claim.


  • Anna Comnena, The Alexiad, 13.11–12. Trans. E.R.A. Sewter. Penguin Books, 1969.
  • William of Tyre, A History of Deeds Done Beyond the Sea, Vol. I, 11.6. Trans. Emily Atwater Babcok and A.C. Krey. Columbia University Press, 1943.
  • Thomas S. Asbridge, The Creation of the Principality of Antioch, 1098–1130. The Boydell Press, 2000.
  • Jonathan Harris, Byzantium and the Crusades. Hambledon and London, 2003.
  • Ralph-Johannes Lilie, Byzantium and the Crusader States, 1096–1204. Trans. J.C. Morris and J.C. Ridings. Clarendon Press, 1993.
  • Kenneth M. Setton, ed., A History of the Crusades, Vols. II and V. Madison, 1969– von Devol

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