Names can be confusing in history, for significant figures often share the same name – There have been eighteen kings Louis in France; eight kings Henry in England and six kings James in Scotland; eleven emperors Constantine in – where else – Constantinople; and six presidents James in the United States. I may add that I hope Canada stops with two Trudeaus, who are more than enough.
Someone this morning asked if the saint we celebrate today, Eusebius of Vercelli (+371), is the same Eusebius who baptized Emperor Constantine – the First – on this deathbed in 337. The answer is no, for that was Eusebius of Nicomedia (+341), who was theologically speaking the opposite of Vercelli, being a vehement Arian, who believed that Christ most definitely was not God, not divine (putting the validity of Constantine’s deliberated delayed baptism into some doubt, for the Arians were wont to use the formula ‘I baptize you in the name of the Father, who is greater, and the Son, who is lesser...).
There is a third famous Eusebius, of Caesarea (+339/40), not far from the place where Christ gave the papal promise to Peter. This Eusebius, who wrote his famous and very influential history of the Church, Ecclesiastical History, was a semi-Arian, which meant that was willing to confess that the Son was very much like the Father (homoi-ousios), but would not commit to full Nicene orthodoxy, that the Son was the same substance/essence as the Father (homo-ousios), fully divine, fully God. All for the sake of one iota!
Our life and our eternity depend on what we think of Christ – Who do men say that I am? – so choose wisely which Eusebius you will follow.