[Helena,] empress, mother of Constantine the great,1 adorned with every virtue. She used to show Christ-like humility to all, but especially toward the sacred order of the monastics. For gathering those women who practice virginity throughout their life, and often even sleeping on a bed of straw, she herself served at table, setting out cooked food and handing out wine cups and pouring water over their hands, she performed the work of a servant. So, too, did she raise her ever-memorable son from childhood to have a spirit without arrogance, to attend to virtue and government with care, to serve God with fear and trembling... For, during the reign of Constantine the Great, the nearer Indians and the Iberians and the Armenians were baptized.2
2 stelae were made to stand in the apse of the chamber of tribute; one for Helena and one for Constantine, with a cross in the middle, saying "one [only is] holy." And 2 stelae likewise in the circus; they were dedicated by the [one] offering tribute.
Sources: first paragraph George the Monk, Chronicon 501.22-502.13; second paragraph ps.-Codinus, Patria Constantinopoleos 2.16 (Preger, Scriptores originum Constantinopolitanarum 158.12-159.2). For the latter cf. sigma 1084.