Author and Editor: Dimitar Dechev (translated from Migne Patrologiae, Series Latina)



Christianization of Bulgaria was the process by which 9th-century medieval Bulgaria converted to Christianity. It was influenced by the Khan's shifting political alliances with the kingdom of the East Franks and the Byzantine Empire, as well as his reception by the Pope. Because of Bulgaria's strategic position, both Rome and Constantinople churches wanted Bulgaria in their diocese. Christianization was considered a means of integrating Slavs into the region. After some overtures to each side, the khan adopted Christianity from Constantinople. Through them, he achieved his goal of gaining an independent Bulgarian national church and having an archbishop appointed to it.

When Khan Boris began his reign in 852, the international situation was very complicated. The conflict with the Byzantine Empire for domination over the Slavic tribes in modern-day Macedonia and Thrace was still far from being resolved. In the middle Danube region, Bulgaria's interests crossed with those of the emerging kingdom of the East Franks and the principality of Great Moravia. It was about that period when Croatia emerged on the international scene, carrying its own ambitions and demands for territories in the region.

On a larger scale, the tensions between Constantinople and Rome were tightening. Both centres were competing to lead the Christianization that would integrate the Slavs in South and Central Europe. The Bulgarian Khanate and the Kingdom of the East Franks had established diplomatic relations as soon as the 20s and 30s of the 9th century. In 852, at the beginning of the reign of Khan Boris, a Bulgarian embassy was sent to Mainz to tell Louis II of the change in Pliska, the Bulgarian capital. Most probably the embassy also worked to renew the Bulgarian-German alliance.

Some time later, Khan Boris concluded an alliance with the Great Moravian Knyaz Rastislav (846-870). The catalyst for this move was the King of the West Franks, Charles the Bald (840-877). The German Kingdom responded by attacking Bulgaria. It defeated Bulgaria and forced Khan Boris to re-establish his alliance with the German king. This alliance was directed against Great Moravia, which was a Byzantine ally. The situation held great risk for the Bulgarian state.

Warfare started between Bulgaria and the Byzantines in 855-856. The Empire wanted to regain control over some fortresses on the Diagonal Road (Via Diagonalis or Via Militaris) that went from Constantinople, through Philippopolis (Plovdiv), to Naissus (Niš) and Singidunum (Belgrade). The Byzantine Empire was victorious and reconquered a number of cities, with Philippopolis being among them.

Khan Boris' alliance with the Germans threatened Great Moravia, which sought help from Byzantium (862-863). This was at the same time when a Byzantine mission to Great Moravia was taking place. Cyril and his brother Methodius intended to draw Great Moravia closer to Constantinople circle and strengthen the Byzantine influence there.

In the last months of 863, the Byzantines attacked Bulgaria again. The most probable reason was that rulers learned of Boris' telling the German king that he wanted to accept Christianity. Byzantium had to forestall Bulgaria from taking up Christianity from Rome. It considered a Rome dependant Bulgaria in the hinterland of Constantinople as a threat to the Byzantine Empire's immediate interests. Byzantium did not demand territories but instead the conversion to Eastern Christianity of Bulgarian representatives and leaders, followed by conversion by the rest of the Bulgarian people. Such a demand would be unacceptable in other circumstances.

The two sides concluded a "deep peace" for a 30-year period. In the late autumn of 863, a mission from the Patriarch of Constantinople came to Pliska and converted the khan, his family and high-ranking dignitaries. They were all baptized as Christians.



Following the conquests of Khan Krum of Bulgaria at the beginning of the 9th century, Bulgaria became an important regional power in Southeastern Europe. Its future development was connected with the Byzantine and East Frankish empires. Since both of these states were Christian, pagan Bulgaria remained more or less in isolation, unable to interact on even grounds, neither culturally nor religiously.

After the conversion of the Saxons, most of Europe was Christian. The preservation of paganism among the Bulgars and the Slavs (the two ethnic groups that formed the Bulgarian people) brought another disadvantage the two ethnic groups' unification was hampered by their different religious beliefs. Lastly, Christianity had its roots in the Bulgarian lands prior to the formation of the Bulgarian state.

As Byzantine missions converted the Bulgarians, their forces encouraged the people to destroy the pagan holy places. Conservative Bulgarian aristocratic circles opposed such destruction, as they had led the spiritual rituals. In 865, malcontents from all ten administrative regions (komitats) revolted against Boris (now titled Knyaz), accusing him of giving them a "bad law". The rebels moved toward the capital intending to capture and kill the knyaz, and to restore the old religion.

All that is known is that Knyaz Boris gathered people loyal to him and suppressed the revolt. He ordered the execution of 52 boyars who were leaders in the revolt, "along with their whole families". The common folk who "wished to do penance" were allowed to go without harm. Historians believe the knyaz executed almost half the Bulgarian aristocracy to end the religious and political conflict. His aristocratic opponents had feared that the Byzantine Empire would spread its influence through Christianity and destroy Bulgaria. At this time during the Middle Ages, Bulgarians considered "Christians" as equivalent to their traditional competitors the "Byzantines", or "Greeks", as they were most often called. Many Bulgarians thought that along with Christianity, they would be forced to accept the Byzantine way of life and morals.

Knyaz Boris realized that the Christianization of his subjects would result in greater Byzantine influence. The liturgy was performed in Greek language, and the newly established Bulgarian Church was subordinate to the Church of Constantinople. The revolt against the new religion prompted the Knyaz to ask Constantinople to allow the Bulgarian Church independent status.

Prior to the middle of the 9th century, in the practice of the formally united Church, there were no precedents for creating national churches among newly converted peoples. Bulgaria created this precedent and set the example for others to follow.

When Constantinople refused to grant the Bulgarian Church independence, Knyaz Boris turned to the Pope. At the end of August 866, a Bulgarian mission led by the kavhan Peter arrived in Rome, carrying a list of 115 questions from Knyaz Boris. These had to do with the Christian way of life of the newly converted Bulgarians and the potential organization of a future Bulgarian Church under Rome's jurisdiction. On 13 November 866, the Bulgarian knyaz received the Pope's 106 answers. Formosa from Portua and Paul of Populon led the Pope's mission. At the same time, the Pope sent other emissaries to Constantinople.

When the Roman clerical mission arrived, Knyaz Boris was sufficiently satisfied with Rome's response that he ordered the Byzantine mission to leave Bulgaria. This was viewed as an official change of Bulgarian orientation from Constantinople to Rome. Seeing Rome's emissaries there, the German mission also left Bulgaria, satisfied that Bulgaria will be in the Roman diocese.

Emperor Michael III was displeased by Bulgaria's banishment of Byzantium's clergy. In a letter to Knyaz Boris, the Byzantine emperor expressed his disapproval of Bulgaria's religious reorientation by using offensive language against the Roman Church. The old rivalry between the two branches of Christianity burned with new power. In less than two years, Bulgaria's name became widely known in Western Europe.

In Constantinople, people nervously watched the events taking place in Bulgaria. They believed a pro-Roman Bulgaria threatened Constantinople's immediate interests. A religious council was held in the summer of 867 in the Byzantine capital, during which clerics criticized the Roman Church's actions of recruiting Bulgaria. Pope Nicholas I was anathematized.

Without losing time, Knyaz Boris asked the Pope to appoint Formosa of Portua as Bulgarian Archbishop. The Pope refused. Nicholas I likely had some personal reasons for his decision, because the official response, that Formosa already had an eparchy, was untrue. The Pope ordered new leaders, Dominic of Trivena and Grimwald of Polimarthia, of a mission to be sent to Bugaria. Soon after, Pope Nicolas I died. His successor, Pope Adrian II (867-872), also failed to respond to Knyaz Boris' request for appointment of a Bulgarian archbishop.

The Knyaz proposed another candidate for Bulgarian archbishop, but the Pope refused. Instead, he suggested a cleric named Silvester. The man was so low in the hierarchy that he was not authorized to carry out liturgy alone. After he had a three-day stay in Pliska, the Bulgarians sent Silverster back to Rome, accompanied by emissaries carrying a letter of complaint by Knyaz Boris. The Knyaz perceived Rome's refusals of his request and delays as an insult and a sign of the Pope's unwillingness to coordinate selection with him of a Bulgarian archbishop.

As a result, Knyaz Boris began negotiations again with Constantinople, where he expected more cooperation than shown in the past. But, on 23 September 867, Emperor Michael III was killed by his close acquaintance Basil, who started the Dynasty of the Macedonians that ruled the Empire until 1057. Patriarch Photius was replaced by his ideological rival Ignatius (847-858; 867-877). Ignatius brought about a change in the relations with the Roman Church.

The new rulers of the Byzantine Empire quickly lessened tensions between Constantinople and Rome. Pope Adrian II needed the help of Basil I against the Arabs' attacks in Southern Italy. At the same time, Byzantium anticipated the Pope's support for Patriarch Ignatius.

As a result of the leaders' agreements, a Church Council was held in Constantinople. After the end of the official conferences, on 28 February 870 Bulgarian emissaries arrived in Constantinople, sent by the Knyaz and led by the Ichirguboil (the first councilor of the Knyaz) Stasis, the Kan-Bogatur (high-ranking aristocrat) Sondoke, and the Kan-Tarkan (high-ranking military commander) among then.

Few people suspected the real purpose of these emissaries. On 4 March 870 Emperor Basil I closed the Council with a celebration at the Emperor's palace. In attendance was the Bulgarian Kavkan (roughly a vice-khan or vice-knyaz) Peter. After he greeted the representatives of the Roman and Byzantine Churches (the Roman being first), Kavkan Peter asked under whose jurisdiction the Bulgarian Church should fall. The Roman representatives were not prepared to discuss this matter.

There appeared to have been a secret agreement between the Byzantine Patriarch, the Emperor and the Bulgarian emissaries. The Orthodox fathers immediately asked the Bulgarians whose clergy they had found when they came to the lands which they now ruled. They answered "Greek". The Orthodox fathers declared that the right to oversee the Bulgarian Church belonged only to the Constantinople Mother Church, which had held jurisdiction on these lands in the past.

The protests of the Pope's emissaries were not taken into account. With the approval of the Knyaz and the Fathers of the Council, the Bulgarian Church was declared autonomous. An Archbishop was to be elected among the bishops with the approval of the Knyaz.

The creation of an independent Bulgarian Archbishopric was unprecedented in the practice of the Churches. Usually, independent churches were those founded by apostles or apostles' students. For a long period, Rome had been challenging Constantinople's claim of equality to Rome, on the grounds that the Church of Constantinople had not been founded by an apostle of Christ.

Just six years after his conversion, the Orthodox Church granted Knyaz Boris a national independent church and a high-ranking supreme representative (the Archbishop). In the next 10 years, Pope Adrian II and his successors made desperate attempts to regain their influence in Bulgaria and to persuade Knyaz Boris to leave Constantinople's sphere.

The foundations of the Bulgarian national Church had been set. The next stage was the implementation of Cyrillic and the Old Bulgarian language, as the official language of the Bulgarian Church and State. But this happened later during the reign of King Simeon Knyaz Boris' successor. Such nationalization of the church and liturgy was exceptional and not at all part of the practice of other European Christians.



Gjuzelev, V. Medieval Bulgaria, Byzantine Empire, Black Sea, Venice, Genoa (Centre culturel du monde byzantin). Verlag Baier, 1988.



Responses of Pope Nicholas I to the Questions of the Bulgars A.D. 866

See also this, text is unintelligible but titled in Bulgarian: "Bulgarski Starini, Kniga V - Poslania na Tsarigradski Patriarch Fotii do Bulgarski Knyaz Boris" (1917) with commentaries in Bulgarian from Prof. V. Zlatarski


Addendum: We are going to expound on three Medieval documents (aka., often referred 'Sources' in Bulgarian historical literature), which had been issued as direct consequence of the Christianization of Bulgaria in a. 863 A. D. The introductory chapter above is taken from Prof. V. Gjuzelev's book on Medieval Bulgaria (1988), but he has also written an earlier and very extensive monograph on the long reign of Knyaz Boris I (1968), where general and detailed bibliography could be consulted. So the three documents we are going to discuss are (not in chronological order but as means of conveying importance):

1. Responses of Pope Nicholas I to the Questions of the Bulgars. These were a sort of consultation. The newly baptized Boris was rather naive man, but not necessarily dull. He believed that with adopting Christianity at state that automatically would grant him independent church. He was not aware technically of the matters of Schism that were running between Rome and Constantinople. The 'filioque' issue taken bluntly meant this whether to praise the Holy Spirit from the name of "the Father" [in the East] or from the name of "the Father and the Son" [in the West]. The initial estrangement turned into aggressiveness especially whence the territories of the former Roman Empire had to be shared. Those were settled already in the 9th c. by varia heathen tribes, the Slavs on the Balkans and Central European Plain making the largest conglomeration. As we see from the excerpt above Boris was one of those rulers that aimed unification of Slavs under the banner of Christianity. The rest are historical details, ephemeral or not.

2. Letter of Patriarch Photius of Constantinople to Khan Boris of Bulgaria. We couldn't download this letter from the Internet. JSTOR was insistent on 10$ bill so we proceeded otherwise. The letter do exist and have its genesis. In 865, malcontents from ten administrative regions (komitats) revolted against Boris (now titled Knyaz), accusing him of giving them a "bad law" (thus referring to Christianity). Boris suppressed the rebellion with much blood and seemingly asked Patriarch Photius what to do with resilient masses. The Patriarch whom authorities of his age had called to be utmost cunning man replied with a "hail". He considered Boris his bastard son and remained long time non-committal. His plan was to emulate the fresh converts into the former provinces of Byzantium and retain their status as eparchies. He sent masons to assist Boris in building churches and accepted learned men as exchange students in Constantinople. The bitterest enemy of the Greeks, the future Tsar Simeon, was amongst them. The brothers Cyril and Methodius from Salonika were also agents of Photius from an earlier period. He should have sent them in Bulgaria while the detour to Great Moravia was further breach with the Pope.

3. Manuals of Byzantine administrative law. The third issue connected with the conversion was the language dispute. Thousands of volumes have been written on the origins of Old Slavonic alphabet (Glagolitic and Cyrillic). I wouldn't reiterate here how dumb and illogical sound the fact that one Christian should give an alphabet for administrative purposes to his Christian adversary. A Chinese or a Hindu would never have done like that. But it was exactly matters of religious practice and concerning civil law, especially the 'Ecloga' of the 8th century and the 'Prochiron' of the 9th, which eventually were translated into Slavic. A Bulgarian compilation of the Byzantine laws, known as the 'Zakon Sudnyi Liudem' ("Court Law for the People"), the original version of which appeared not later than the 10th century (it may go back to the Cyrillo-Methodian period) was the first official Bulgarian document. No copies are preserved in Bulgaria and later it became amalgamated as the 'Kormchaja Kinga" ("Pilot Book") in some collections of Russian law of the 12th and early 13th centuries. The 'Nomocanon' (first that of Johannes Scholasticus, later that of Patriarch Photius) was used to settle questions of ecclesiastical and canon law. The first translation of the "Nomocanon" into Russian took place in the 11th and 12th centuries.

I have tried to be explicit but not exhaustive in this short compilation. Naturally, further reading is necessary to comprehend how those homilies and 'zakoni' worked on the primitive mind of an uneducated peasant from the Middle Ages. Browsing the Bulgarian edition of "Responsa Nicolai Papae I ad Consulta Bulgarororum" (1922) we could make several reflections. The translation and annotations are made by Prof. Dimitar Dechev titular at Department of Latin Language, Historico-Philological Faculty, Sofia University. Prof. D. Dechev worked in Bulgaria before and after World War II. Many of the Latin classic works are firstly his translation. Specifically, this edition of "Responsa ..." is not the first Bulgarian translation, however, it is the fullest. Before him Nikola Blagoev (1915) and S. S. Bobchev (1903) delved with the responses of Pope Nicholas I and tried to restore the original questionnaire sent by Knyaz Boris. They hypothetically rendered a list of 106 questions (Q. from I to CVI). Prof. Vasil Zlatarski (1912) made a useful meta-analysis of the whole material and presented a correspondence table of the different titles. Finally, a wide number of Russian professionals from 19th c. did scholarly research on the issue and left many important monographs. Those serve as instigation for Modern Slavic Studies even today, ditto.


Picture 1: Sample illustration on the text above.

(i). Prof. Vasil Zlatarski's correspondence table of different law titles as presented in Responsa (col. 1-2), Ecloga (col. 3), Nomocanon (col. 4) and Zakon Sudnyi Liudem (col. 5-7).



Copyright 2013 by the author.