Successor of Marcellus, 309 or 310. His reign was short. The Liberian Catalogue gives its duration as only four months, from 18 April to 17 August, 309 or 310. We learn some details of his career from an epitaph for his tomb which Pope Damasus ordered. This epitaph had come down to us through ancient transcripts. A few fragments of the original, together with a sixth-century marble copy made to replace the original, after its destruction were found by Di Rossi in the Papal Chapel, in the catacombs of Callistus. It appears from this epitaph that the grave internal dissentions caused in the Roman Church by the readmittance of the apostates (lapsi) during the persecution of Diocletian, and which had already arisen under Marcellus, continued under Eusebius. The latter maintained the attitude of the Roman Church, adopted after the Decian persecutions (250-51), that the apostates should not be forever debarred from ecclesiastical communion, but on the other hand, should be readmitted only after doing proper penance (Eusebius miseros docuit sua crimina flere).

This view was opposed by a faction of Christians in Rome under the leadership of one Heraclius. Whether the latter and his partisans advocated a more rigorous (Novationist) or a more lenient interpretation of the law has not been ascertained. The latter, however, is by far more probable in the hypothesis that Heraclius was the chief of a party made up of apostates and their followers, who demanded immediate restoration to the body of the Church. Damasus characterizes in very strong terms the conflict which ensued (seditcio, cœ, bellum, discordia, lites). It is likely that Heraclius and his supporters sought to compel by force their admittance to divine worship, which was resented by the faithful gathered in Rome about Eusebius. In consequence both Eusebius and Heraclius were exiled by Emperor Maxentius. Eusebius, in particular, was deported to Sicily, where he died soon after. Miltiades ascended the papal throne, 2 July, 311. The body of his predecessor was brought back to Rome, probably in 311, and 26 September (according to the "Depositio Episcoporum" in the chronographer of 354) was placed in a separate cubiculum of the Catacomb of Callistus. His firm defense of ecclesiastical discipline and the banishment which he suffered therefor caused him to be venerated as a martyr, and in his epitaph Pope Damasus honours Eusebius with this title. His feast is yet celebrated on 26 September.

Liber pontificalis, ed. DUCHESNE, I, 167; DE ROSSI, Roma sotterranea, II (Rome 1867), 191-210: NORTHCOTE AND BROWNLOW, Roma sotterranea, 2nd ed. (London, 1879); LIGHTFOOT, Apostolic Fathers, 2nd ed. I, I, 297-299; IHM, Damasi Epigrammata (Leipzig, 1895), 25, num. 18; Acta SS., Sept., VII, 265-271; Carini I lapsi e la deportazione in Sicilia del Papa S. Eusebio (Rome, 1886); LANGEN, Geschichte der romischen Kirche, I (Bonn, 1881), 380-382.