Library Eusebius of Caesarea Church History
Book 7, Chapter 2: The Bishops of Rome in those Times.
Cornelius, having held the episcopate in the city of Rome about three years, was succeeded by Lucius. He died in less than eight months, and transmitted his office to Stephen. Dionysius wrote to him the first of his letters on baptism, as no small controversy had arisen as to whether those who had turned from any heresy should be purified by baptism. For the ancient custom prevailed in regard to such, that they should receive only the laying on of hands with prayers.
English translation by Arthur Cushman McGiffert, in Nicene and Post-Nicene Fathers, Series II, Vol. I (eds. Philip Schaff and Henry Wace; Buffalo: Christian Literature Publishing Co., 1890). Public domain. Digital text via New Advent Church Fathers.