In the third year of the same reign, Alexander, bishop of Rome, died after holding office ten years. His successor was Xystus. About the same time Primus, bishop of Alexandria, died in the twelfth year of his episcopate, and was succeeded by Justus.
Historia Ecclesiastica
Book IV, Chapter 4. The Bishops of Rome and of Alexandria under the Same Emperor
1 section
Eusebius of Caesarea
Trans. Arthur Cushman McGiffert, A Select Library of Nicene and Post-Nicene Fathers of the Christian Church, Second Series, Volume I, 1890. Public domain.