NPNF2-01. Eusebius Pamphilius: Church History, Life of Constantine, Oration in Praise of Constantine

Chapter XLVIII.—Celebration of Constantine’s Decennalia.

While he was thus circumstanced, he completed the tenth year of his reign. On this occasion he ordered the celebration of general festivals, and offered prayers of thanksgiving to God, the King of all, as sacrifices without flame or smoke.³¹⁴⁸ And from this employment he derived much pleasure: not so from the tidings he received of the ravages committed in the Eastern provinces.