The Bulgarian Orthodox Church (), legally the Patriarchate of Bulgaria (), is an autocephalous Eastern Orthodox jurisdiction based in Bulgaria. It is the oldest Slavic Orthodox church, with some 6 million members in Bulgaria and between 1.5 and 2 million members in a number of other European countries, Asia, the Americas, Australia, and New Zealand. It was recognized as autocephalous in 1945 by the Ecumenical Patriarchate of Constantinople.
History
Early Christianity
The Bulgarian Orthodox Church has its origin in the flourishing Christian communities and churches set up in the Southeast Europe as early as the first centuries of the Christian era. Christianity was brought to Thracian lands by the apostles Paul and Andrew in the 1st century AD, when the first organised Christian communities were formed. By the beginning of the 4th century, Christianity had become the dominant religion in the region. Towns such as Serdica (Sofia), Philipopolis (Plovdiv), Odessus (Varna), Dorostorum (Silistra) and Adrianople (Edirne) were significant centres of Christianity in the Roman Empire.
The Monastery of Saint Athanasius, the first Christian monastery in Europe, was founded in Thrace in 344 by Saint Athanasius near modern-day Chirpan, Bulgaria, following the Council of Serdica and the Edict of Serdica.
The raids and incursions into the Roman provinces in the 4th and the 5th centuries brought considerable damage to the ecclesiastical organisation of the Christian Church in the Bulgarian lands, yet did not destroy it. Kubrat and Organa were both baptized together in Constantinople and Christianity started to pave its way from the surviving Christian communities to the surrounding Bulgar-Slavic mass. By the middle of the 9th century, the majority of the Bulgarian Slavs, especially those living in Thrace and Macedonia under Eastern Roman rule, were Christianized. The process of conversion also enjoyed some success among the Bulgar nobility. However, it was not until the official adoption of Christianity in state level by Boris I in 865 that an independent Bulgarian ecclesiastical entity was established.
Establishment
Boris I believed that cultural advancement and the sovereignty and prestige of a Christian Bulgaria could be achieved through an enlightened clergy governed by an autocephalous church. To this end, he manoeuvred between the Patriarch of Constantinople and the Roman Pope for a period of five years until in 870 AD, the Fourth Council of Constantinople granted the Bulgarians an autonomous Bulgarian archbishopric. The archbishopric had its seat in the Bulgarian capital of Pliska, and its diocese covered the whole territory of the Bulgarian state. The tug-of-war between Rome and Constantinople was resolved by putting the Bulgarian archbishopric under the jurisdiction of the Patriarch of Constantinople and the Orthodox Church, from whom it obtained its first primate, its clergy, and theological books.
Although the archbishopric enjoyed full internal autonomy, the goals of Boris I were scarcely fulfilled. A Greek liturgy offered by a Byzantine clergy furthered neither the cultural development of the Bulgarians, nor the consolidation of the Bulgarian Empire; it would have eventually resulted in the loss of both the identity of the people and the statehood of Bulgaria. Following the Byzantine theory of "Imperium sine Patriarcha non staret", which said that a close relation should exist between an Empire and Patriarchate, Boris I greeted the arrival of the disciples of the recently deceased Saints Cyril and Methodius in 886 as an opportunity. Boris I gave them the task of instructing the future Bulgarian clergy in the Glagolitic alphabet and the Slavonic liturgy prepared by Cyril. The liturgy was based on the vernacular of the Bulgarian Slavs from the region of Thessaloniki. In 893, Boris I expelled the Greek clergy from the country and ordered the Greek language to be replaced with the Slav-Bulgarian vernacular.
Autocephaly and Patriarchate
Following Bulgaria's two decisive victories over the Byzantines at Acheloos (near the present-day city of Pomorie) and Katasyrtai (near Constantinople), the government declared the autonomous Bulgarian Archbishopric as autocephalous and elevated it to the rank of Patriarchate at an ecclesiastical and national council held in 919. After Bulgaria and the Byzantine Empire signed a peace treaty in 927 that concluded the 20-year-long war between them, the Patriarchate of Constantinople recognised the autocephalous status of the Bulgarian Orthodox Church and acknowledged its patriarchal dignity.
