Finally, Eusebius in his History (5.28) states Zephyrinus succeeded him "about the ninth year of Severus", (201), while the Liber Pontificalis dates it to the consulate of Laternus and Rufinus (197).

Prior to his elevation, a difference in dating the celebration of the Christian Passover/Easter between Rome and the bishops of Asia Minor had been tolerated by both the Roman and Eastern churches.

Synods were held on the subject in various parts—in Judea under Theophilus of Caesarea and Narcissus of Jerusalem, in Pontus under Palmas, in Gaul under Irenaeus, in Corinth under its bishop, Bachillus, at Osrhoene in Mesopotamia, and elsewhere—all of which disapproved of this practice and consequently issued by synodical letters declaring that "on the Lord's Day only the mystery of the resurrection of the Lord from the dead was accomplished, and that on that day only we keep the close of the paschal fast" (Eusebius H. E. v. 23).

Victor alone was intolerant of this difference, and severed ties with these ancient churches, whose bishops included Polycrates of Ephesus;[6] in response he was rebuked by Irenaeus and others, according to Eusebius.

In response to the ruling of the synod and the command issued by Victor I, the churches of the East, led by Polycrates, wrote a reply that is recorded by Eusebius the historian as such:[7] We observe the exact day; neither adding, nor taking away.

Why need I mention the bishop and martyr Sagaris who fell asleep in Laodicea, or the blessed Papirius, or Melito, the Eunuch who lived altogether in the Holy Spirit, and who lies in Sardis, awaiting the episcopate from heaven, when he shall rise from the dead?

And they, beholding my littleness, gave their consent to the letter, knowing that I did not bear my gray hairs in vain, but had always governed my life by the Lord Jesus.These events and Victor's response to Polycrates' letter are recorded by Socrates Scholasticus as such: "In Asia Minor most people kept the fourteenth day of the moon, disregarding the sabbath: yet they never separated from those who did otherwise, until Victor, bishop of Rome, influenced by too ardent a zeal, fulminated a sentence of excommunication against the Quartodecimans in Asia.