Of Lucifer and Eusebius
About the same time Lucifer and Eusebius were by an imperial order, recalled from banishment out of the Upper Thebaïs; the former being bishop of Carala, a city of Sardinia, the latter of Vercellæ, a city of the Ligurians in Italy, as I have said previously. These two prelates therefore consulted together on the most effectual means of preventing the neglected canons and discipline of the church from being in future violated and despised.
Source: Ecclesiastical History (New Advent)