In his parents' house, however, this decision was seen under various aspects.

His father found little to say against it, for he had three sons and only two shipyards, and the question seemed settled by the fact that Constantine, with his resolute and powerful nature, was cut out to be a soldier.

His pious mother, on the other hand, appealed to the learned works of Clemens and Tertullian, who forbid the faithful Christian to draw the sword; and she related the legend of the holy Maximilianus, who, being compelled, under Diocletian, to join the army, had suffered death at the hands of the executioner rather than shed his fellow-creatures' blood in battle.

The use of weapons, she added, was incompatible with a godly and Christian life.
His father, however, would not listen to this reasoning; new times, he said, were come; the greater part of the army had been baptized; the Church prayed for, victory, and at the head of the troops stood the great Theodosius, an exemplar of an orthodox and zealous Christian.
Clemens was master in his own house, and Constantine joined the heavy cavalry at Arsinoe.

In the war against the Blemmyes he was so fortunate as to merit the highest distinction; after that he was in garrison at Arsinoe, and, as Alexandria was within easy reach of that town, he was in frequent intercourse with his own family and that of Porphyrius.