Ante-Nicene Fathers, Vol VII:
Lactantius: Chap. XLIII

Chap. XLIII.

Of the adversaries of God there still remained one, whose overthrow and end I am now to relate.  

Daia had entertained jealousy and ill-will against Licinius from the time that the preference was given to him by Galerius; and those sentiments still subsisted, notwithstanding the treaty of peace lately concluded between them. When Daia heard that the sister of Constantine was betrothed to Licinius, he apprehended that the two emperors, by contracting this affinity, meant to league against him; so he privily sent ambassadors to Rome, desiring a friendly alliance with Maxentius: he also wrote to him in terms of cordiality. The ambassadors were received courteously, friendship established, and in token of it the effigies of Maxentius and Daia were placed together in public view. Maxentius willingly embraced this, as if it had been an aid from heaven; for he had already declared war against Constantine, as if to revenge the death of his father Maximian. From this appearance of filial piety a suspicion arose, that the detestable old man had but feigned a quarrel with his son that he might have an opportunity to destroy his rivals in power, and so make way for himself and his son to possess the whole empire. This conjecture, however, had no foundation; for his true purpose was to have destroyed his son and the others, and then to have reinstated himself and Diocletian in sovereign authority.