Adrian having died after a reign of twenty-one years, was succeeded in the government of the Romans by Antoninus, called the Pious. In the first year of his reign Telesphorus died in the eleventh year of his episcopate, and Hyginus became bishop of Rome.
Christianity · Church History · Ecclesiastical History
Book IV, Ch. 10 — The Bishops of Rome and of Alexandria during the Reign of Antoninus.
Ecclesiastical History · Eusebius of Caesarea