Blastus was a 2nd-century leader of the Roman Montanists, a presbyter in Rome and a Quartodeciman, however likely born in Alexandria. Blastus caused a schism in Rome about Easter and gained many followers. Some scholars have argued that the hostility of Pope Victor I against the Quartodecimans, was caused by Blastus' schism. Blastus argued that Christians must keep Easter at the same time commanded in the Book of Exodus.[1][2][3][4][5][6] Blastus was accused of judaizing the Church by pseudo-Tertullian. Irenaeus wrote a letter to Blastus called "on Schism" which is no longer extant.[6]
Eusebius mentions Blastus along with Florinus stating:[7]
Others, of whom Florinus was chief, flourished at Rome. He fell from the presbyterate of the Church, and Blastus was involved in a similar fall. They also drew away many of the Church to their opinion, each striving to introduce his own innovations in respect to the truth.