Treaty of Devol The Treaty of Devol ( ) was an agreement made in 1108 between Bohemond I of Antioch and Byzantine Emperor Alexios I Komnenos , in the wake of the First Crusade . It is named after the Byzantine fortress of Devol ( in modern Albania ) . Although the treaty was not immediately enforced , it was intended to make the Principality of Antioch a vassal state of the Byzantine Empire . At the beginning of the First Crusade , Crusade r armies assembled at Constantinople and promised to return to the Byzantine Empire any land they might conquer . However , Bohemond , the son of Alexios ' former enemy Robert Guiscard , claimed the Principality of Antioch for himself . Alexios did not recognize the legitimacy of the Principality , and Bohemond went to Europe looking for reinforcements . He launched into open warfare against Alexios , but he was soon forced to surrender and negotiate with Alexios at the imperial camp at Diabolis ( Devol ) , where the Treaty was signed . Under the terms of the Treaty , Bohemond agreed to become a vassal of the Emperor and to defend the Empire whenever needed . He also accepted the appointment of a Greek Patriarch . In return , he was given the titles of " sebastos " and " doux " ( duke ) of Antioch , and he was guaranteed the right to pass on to his heirs the County of Edessa . Following this , Bohemond retreated to Apulia and died there . His nephew , Tancred , who was regent in Antioch , refused to accept the terms of the Treaty . Antioch came temporarily under Byzantine sway in 1137 , but it was not until 1158 that it truly became a Byzantine vassal . The Treaty of Devol is viewed as 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 Europe an neighbors . Background . In 1097 , the Crusader armies assembled at Constantinople having traveled in groups eastward through Europe . Alexios I , who had requested only some western knights to serve as mercenaries to help fight the Seljuk Turks , blockaded these armies in the city and would not permit them to leave until their leaders swore oath s promising to restore to the Empire any land formerly belonging to it 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 Bohemond , probably never intended to honor their promise . In return , Alexios gave them guides and a military escort . The Crusaders were however 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 Alexios , who was able to recover a number of important cities and islands , and in fact much of western Asia Minor , 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 , Alexios marched out to meet them , but , hearing from Stephen of Blois that the situation was hopeless , he returned to Constantinople . The Crusaders , who had unexpectedly withstood the siege , believed Alexios had abandoned them and considered the Byzantines completely untrustworthy . Therefore , they regarded their oaths as invalidated . By 1100 , there were several Crusader states , including the Principality of Antioch , founded by Bohemond in 1098 . It was argued that Antioch should be returned to the Byzantines , despite Alexios ' s supposed betrayals , but Bohemond claimed it for himself . Alexios , of course , disagreed ; Antioch had an important port , was a trade hub with Asia and 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 . Alexios therefore did not recognize the legitimacy of the Principality , believing it should be returned to the Empire according to the oaths Bohemond had sworn in 1097 . He therefore set about trying to evict Bohemond from Antioch . Bohemond added a further insult to both Alexios and the Orthodox Church in 1100 when he appointed Bernard of Valence as the Latin Patriarch , and the same time expelled the Greek Patriarch , John the Oxite , who fled to Constantinople . Soon after , Bohemond was captured by the Danishmends of Syria and was imprisoned for three years , during which the Antiochenes chose his nephew Tancred as regent . After Bohemond 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 . Bohemond left Tancred in control of Antioch and returned in the West , touring Italy and France for reinforcements . He won the backing of Pope Paschal II and the support of the French King Philip I , whose daughter he married . It is unclear whether his expedition qualified as a crusade . Bohemond ' 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 most formidable enemies . While Bohemond was away , Alexios 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 , Bohemond instead launched into open warfare against Alexios , crossing the Adriatic to besiege Dyrrhachium , the westernmost city of the Empire . Like his father however , Bohemond was unable to make any significant advances into the Empire ' s interior ; Alexios avoided a pitched battle and Bohemond ' s siege failed , partly due to a plague among his army . Bohemond soon found himself in an impossible position , isolated in front of Dyrrhachium : his escape by sea was cut off by the Venetians , and Paschal II withdrew his support . Settlements . In September 1108 , Alexios requested that Bohemond negotiate with him at the imperial camp at Diabolis ( Devol ) . Bohemond had no choice but to accept , now that his disease - stricken army would no longer be able to defeat Alexios 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 Alexios , in Bohemond ' s eyes , had also violated the agreement by turning back from the siege of Antioch in 1098 . Alexios agreed to consider the oaths of 1097 invalid . The specific terms of the treaty were negotiated by the general Nikephoros Bryennios , and were recorded by Anna Komnene : The terms were negotiated according to Bohemond ' s western understanding , so that he saw himself as a feudal vassal of Alexios , a " liege man " ( " homo ligius " or ) with all the obligations this implied , as customary in the West : he was obliged to bring military assistance to the Emperor , except in wars in which he was involved , and to serve him against all his enemies , in Europe and in Asia . Anna Komnene described the proceedings with very repetitive details , with Bohemond frequently pointing out his own mistakes and praising the benevolence of Alexios and the Empire ; the proceedings must have been rather humiliating for Bohemond . On the other hand , Anna ' s work was meant to praise her father and the terms of the treaty may not be entirely accurate . The oral agreement was written down in two copies , one given to Alexios , and the other given to Bohemond . According to Anna , the witnesses from Bohemond ' 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 Bohemond ' s army ) . From Alexios ' imperial court , the treaty was witnessed by the " sebastos " Marinos of Naples , 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 . Many of Alexios ' witnesses were themselves Westerners , who held high positions in the Byzantine army and at the imperial court ; Basil and Constantine were ambassadors in the service of Bohemond ' s relatives in Sicily . Neither copy survives . It may have been written in Latin , Greek , or both . Both languages are equally likely given the number of westerners present , many of whom would have known Latin . It is not clear how far Bohemond ' s concessions were known across Latin Europe as only a few chroniclers mention the treaty at all ; Fulcher of Chartres simply says that Bohemond and Alexios were reconciled . Analysis . The Treaty was weighted in Alexios ' favor and provided for the eventual absorption of Antioch and its territory into the Empire . Alexios , recognizing the impossibility of driving Bohemond out of Antioch , tried to absorb him into the structure of Byzantine rule , and put him work for the Empire ' s benefit . Bohemond was to retain Antioch until his death with the title of " doux " , unless the emperor ( either Alexios or , in the future , John ) chose for any reason to renege on the deal . The principality would revert to direct Byzantine rule on Bohemond ' s death . Bohemond therefore could not set up a dynasty in Antioch , although he was guaranteed the right to pass on to his heirs the County of Edessa , and any other territories he managed to acquire in the Syrian interior . Bohemond ' s lands were to include St Simeon and the coast , the towns of Baghras and Artah , and the Latin possessions in the Jebel as - Summaq . Latakia and Cilicia , however , were to revert to direct Byzantine rule . As Thomas Asbridge points out , much of what the Emperor granted to Bohemond ( including Aleppo itself ) was still in Muslim hands ( e . g . neither Bohemond nor Alexios controlled Edessa , although at the time Tancred was regent there as well as in Antioch ) , which contradicts Lilie ' s assessment that Bohemond did well out of the Treaty . René Grousset calls the Treaty a " " Diktat " " , but Jean Richard underscores that the rules of feudal law to which Bohemond had to submit " were in no way humiliating . " According to John W . Birkenmeier , the Treaty marked the point at which Alexios had developed a new army , and new tactical doctrines with which to use it , but it was not a Byzantine political success ; " it traded Bohemond ' s freedom for a titular overlordship of Southern Italy that could never be effective , and for an occupation of Antioch that could never be carried out . " The terms of the Treaty have been interpreted in various ways . According to Paul Magdalino and Ralph - Johannes Lilie , " the Treaty as reproduced by Anna Komnene shows an astonishing familiarity with western feudal custom ; whether it was drafted by a Greek or by a Latin in imperial service , it had a sensitive regard for the western view of the " status quo " in the East Mediterranean . " So too did the diplomatic initiatives Alexios undertook , in order to enforce the Treaty on Tancred ( such as the treaty he concluded with Pisa in 1110 – 1111 , and the negotiations for Church union with Pascal II in 1112 ) . In contrast , Asbridge has recently argued that the Treaty derived from Greek as well as western precedents , and that Alexios wished to regard Antioch as falling under the umbrella of " pronoia " arrangements . Aftermath . Bohemond never returned to Antioch ( he went to Sicily where he died in 1111 ) , and the carefully constructed clauses of the Treaty were never implemented . Bohemond ' s nephew , Tancred , refused to honor the Treaty . 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 Alexios had tricked Bohemond into giving him Antioch ; they already believed Alexios was devious and untrustworthy and this may have confirmed their beliefs . The treaty referred to Tancred as the illegal holder of Antioch , and Alexios had expected Bohemond 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 . Although the Treaty of Devol never came into effect , it provided the legal basis for Byzantine negotiations with the crusaders for the next thirty years , and for imperial claims to Antioch during the reigns of John II and Manuel I . Therefore , John II attempted to impose his authority , traveling to Antioch himself in 1137 with his army and besieging the city . The citizens of Antioch tried to negotiate , but John demanded the unconditional surrender of the city . After asking the permission of the King of Jerusalem , Fulk , which he received , Raymond , the Prince of Antioch , agreed to surrender the city to John . The agreement , by which Raymond swore homage to John , was explicitly based on the Treaty of Devol , but went beyond it : Raymond , who was recognized as an imperial vassal for Antioch , promised the Emperor free entry to Antioch , and undertook to hand over the city in return for investiture with Aleppo , Shaizar , Homs and Hama as soon as these were conquered from the Muslims . Then , Raymond would rule the new conquests and Antioch would revert to direct imperial rule . The campaign finally failed , however , partly because Raymond and Joscelin II , Count of Edessa , who had been obliged to join John as his vassals , did not pull their weight . When , on their return to Antioch , John insisted on taking possession of the city , the two princes organized a riot . John found himself besieged in the city , and was forced to leave in 1138 , recalled to Constantinople . He diplomatically accepted Raymond ' s and Joscelin ' s insistence that they had nothing to do with the rebellion . John repeated his operation in 1142 , but he unexpectedly died , and the Byzantine army retired . It was not until 1158 , during the reign of Manuel I , that Antioch truly became a vassal of the empire , after Manuel forced Prince Raynald of Châtillon 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 . In the Balkan frontier , the Treaty of Devol marked the end of the Norman threat to the southern Adriatic littoral during Alexios ' reign and later ; the efficacy of the frontier defenses deterred any further invasions through Dyrrachium for most of the 12th century .