Library Eusebius of Caesarea Church History
Book 7
Chapter 1: The Wickedness of Decius and Gallus
When Decius had reigned not quite two years, he was slain with his children, and Gallus succeeded him. At this time Origen died, being sixty-nine years of age. Dionysius, writing to Hermammon, speaks as follows of Gallus:
Gallus neither recognized the wickedness of Decius, nor considered what had destroyed him; but stumbled on the same stone, though it lay before his eyes. For when his reign was prosperous and affairs were proceeding according to his mind, he attacked the holy men who were interceding with God for his peace and welfare. Therefore with them he persecuted also their prayers in his behalf.
So much concerning him.
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.