MESIA, EVANGELIZATION of. — The name M., which appears only with the Roman conquest, did not retain a constant geographical meaning throughout the history of the Empire. In very general terms, it may be said that the region so called was bounded to the south by the Haemus range (Balkans), to the north by the course of the Lower Danube, to the east by the Black Sea, and to the west by the course of the Drin and by the mountains bordering Bosnia and Dalmatia.
The territory began to be traversed by Roman armies in the last century of the Republic; it was constituted as a province by Augustus and then reorganized by Tiberius after the Pannonian revolt. Domitian divided it into two provinces, Moesia Superior (Serbia) and Moesia Inferior (parts of Bulgaria and Romania as far as the mouths of the Danube). Later, when Aurelian, under persistent barbarian pressure, definitively abandoned the lands north of the Danube (Dacia), he transferred south of the river not only the garrisons of that province but also, as a favorable omen, its name, creating at the expense of Upper M. two new provinces: Dacia ripuaria and Dacia mediterranea.
Christian preaching, as presented in the Actus Apostolorum, did not reach M.; but since those Actus are essentially the Actus Pauli, the tradition recorded by Eusebius, which brings the evangelical mission of the apostle Andrea to these remote Danubian regions (Eusebius, Hist. eccl., III, 1), might not be entirely rejected, without thereby placing credence in the so-called Acts of Andrea, which are certainly apocryphal (J. Flamion, Les Actes apocryphes d'André, Lovanio 1911). It is, moreover, quite plausible to suppose that the flourishing ancient Christian communities of Thrace and Macedonia (Philippi, Beroea, Thessalonica) spread into nearby M.
It has even been thought that a Jallius Bassus, governor of Lower M. in 161 (CIL, III, 6169), may have been a Christian, since his name was found as the father of a Jallia buried in a Christian sarcophagus in the cemetery of Callistus (O. Marucchi, Le catacombe romane, Roma 1933, p. 227). The first positive documents would rather be the Passiones of certain martyrs during the persecution of Diocletian. It is known that during that persecution great concern was devoted to eliminating Christian infiltration from the ranks of the army; consequently, the martyrdom of six soldiers from the Danubian garrisons (Giulio, Esichio, Nicandro, Marciano, Pasicrate, Valentione) also seems admissible to H. Delehaye (v. BIBLICA). The report of the martyrdom at Sirmium of a presbyter, Montano, also seems reliable. The circumstances recounted concerning the execution of the martyr Dasio are less worthy of credence, but his existence and condemnation are admissible; his body, which was venerated, was transferred to Ancona and provided with a Greek inscription judged to belong to the fifth century (F. Cumont, in Anal. Boll., 27 [1908], p. 370). A final martyr of M. would be the soldier Emiliano, condemned under Julian the Apostate for damaging a pagan altar (F. Cabrol, V. BIBLICA.). Even before the edicts of Galerius, Constantine, and Licinius, which granted Christians the free exercise of their worship, Christian communities seem to have existed in several places in M. (Singidunum, Ratiaria, Durostorum, Axiopolia, Noviodunum, Tomi, Romuliana: Lattanzio, De mortibus persecutorum, XI, 1). Once those edicts had brought peace to the Church, ecclesiastical hierarchies that were fully constituted are immediately found in a considerable number of the cities of M. Episcopal sees existed between the fourth and sixth centuries at Viminacium, Marcianopolis, Singidunum, Margum, Ratiaria, Acqua, Castra Martis, Oescus, Sardica, Naissus, Remesiana, Pautalia, Iustiniana Prima, Iustiniana Secunda, Neutina, Diocletiana, Mariana, Zappara, and Stobi. The names of bishops are preserved in the subscriptions to the Councils of Nicaea (325), Ephesus (341), Sardica (343), Constantinople (381), and in other documents.
Such luxuriant flourishing of Christianity did not, however, remain free from heretical deviations; the doctrines of Nestorio found sympathy and a following among some bishops of M., but Arianism in particular took strong root here, as attested by a letter of s. Ambrogio (Epist., II), a passage of Sozomeno (Hist. eccl., VII, 17), and the records of Arian bishops: Ursacius and Secundianus at Singidunum between 355 and 370, Dominus at Marcianopolis at approximately the same time, and Auxenius at Durostorum after 380.