Several remains of early Christian churches are found throughout the region, and ecclesiastic histories record martyrs in all the major urban centres.
Bishop Ephrem, killed on 7 March 304 in Tomis (modern Constanţa), was the first known Christian martyr of this region, persecution continuing under the emperors Diocletian, Galerius, Licinius and Julian the Apostate.
Besides Zoticos, Attalos, Kamasis and Filippos, who suffered martyrdom under Diocletian (304–305), the relics of two previous martyrs, who witnessed and died during the repression of Emperor Decius (249–251), were unearthed under the crypt.
The Scythian monks made an important contribution to christology, by advocating what has come to be known as the Theopaschite formula as a solution to controversies about the nature of Christ arising after the Council of Chalcedon.
The Council of Chalcedon had attempted to settle the Nestorian and the Monophysite controversies by approving Pope Leo's Tome, confessing that Christ had two natures in one person.
They put forward a christology which drew heavily on Cyril of Alexandria (the formula of the oneness of Christ’s nature as the incarnation of God the Word), emphasizing the unity of Christ, while advocating the Augustinian doctrine of grace, emphasizing the role of grace and eliminating independent human effort from the performance of good works and salvation.
The monks initially won the support of Vitalian, an East Roman general who was the magister militum of Thrace and the leader of a powerful pro-Chalcedonian rebellion against Emperor Anastasius I, who was a convinced Monophysite.
The rebellion started in 512, when a nearly identical formula to that of the Scythian monks, added to the Trisagion in the liturgy of Hagia Sophia, was removed by Emperor Anastasius II.
By the reign of Anastasius' successor, Justin I, orthodoxy extended even to the army: soldiers were ordered to subscribe to the creed of Chalcedon or be deprived of their rations.
At the beginning of the year 519, a delegation of Scythian monks traveled to Constantinople under the leadership of John Maxentius to bring their case before Emperor Justin I, proposing a new solution by arguing in favor of their formula.
Acacius had advised Emperor Zeno to issue a statement, the Henotikon (the "act of union"; 482), which was an attempt to reconcile the differences between the supporters of Orthodoxy and of Monophysitism.
By the time the monks arrived in Constantinople, the political landscape changed and Emperor Justin's policies were directed more to the west than to the east where the Monophysites were dominant.
Failing to gain acceptance in Constantinople, some of the monks, led by John Maxentius, proceeded to Rome in 519, in hopes of winning Pope Hormisdas' support.
Shortly after 13 August 520, their behavior in Rome prompted Pope Hormisdas to write a letter to the same Possessor in Constantinople, criticizing their theology and severely condemning their vociferous objections.
One historian has suggested that after this episode, Maxentius retreated to the religious community living at Tintagel in Sub-Roman Britain, and that his name is mentioned in the Latin inscription on the Artognou stone.
[2] In the end, the Scythian monks found support first from one quarter: they wrote a letter to the bishops of North Africa who at that time were exiled by the Vandals to the island of Sardinia.
The leader of the north-African bishops, Fulgentius of Ruspe composed a reply by which they accepted the christological formula as well as the monks' Augustinian doctrine of grace.
Cassian, together with Athanasius of Alexandria and John Chrysostom, emphasized the idea of an ascent to God through periods of purgation and illumination that led to unity with the Divine.
At Rome, Pope Gelasius had appointed Dionysius Exiguus, a member of the Roman monks community whom he knew from Constantinople, to translate documents in the papal archive.