REGENSBURG, re'gens-bûrg", BISHOPRIC OF: A German diocese founded in the eighth century. Christianity evidently entered Regensburg previous to the reign of Constantine, but after the Romans withdrew, the community of Roman Christians disappeared. After the refoundation of the city, when the Bavarians had conquered the country, the ducal house of Agilolfings, apparently of Frankish descent, was Christian, and it may be conjectured that here, as in Bavaria, the land became Christianized through the combined influence of the Franks and of Celtic missionaries. Although the region was long controlled by abbots with quasi-episcopal authority, it was not until the eighth century that the see of Regensburg was formally erected. For more than two centuries a Benedictine monastery took the place of a cathedral chapter, but in 974 the diocese and abbey were separated. The ancient diocese was practically conterminous with the modern, for though Bohemia was long administered as a missionary province of Regensburg, Bishop Wolfgang (971-994) surrendered it so that it might be made a separate see.
With the Reformation Regensburg became a stronghold of Protestantism, and the adherents of the ancient faith were compelled to struggle against intense opposition. Nevertheless, constant efforts were made to reform all that was amiss in matters pertaining to the Roman church, and education made progress, especially under Jesuit auspices. The campaigns of Gustavus Adolphus in the seventeenth century again struck heavily at the diocese, but after this peril was over, the Roman Catholics of Regensburg once more bent every effort to the improvement of religion and education. From 1805 to 1817 Regensburg was made a metropolitan see of somewhat uncertain ecclesiastical standing, and in the latter year was degraded to a suffragan diocese of Munich-Freising. In 1821, however, it regained the independence as a separate see which it still enjoys. It now forms part of the archdiocese of Munich-Freising, and had, in 1909, 470 parishes and 32 deaneries, 1,086 secular and 147 regular priests, a seminary and lyceum at Regensburg, and a Roman Catholic population of 826,751.