St. Theonas was bishop of Alexandria and a martyr for the faith. He succeeded
St. Maximus in that patriarchal chair in 282, and held it almost nineteen
years, being himself, by the shining light of his sanctity and learning, the
greatest ornament of that church at a time when it was in both respects most
flourishing. St. Pierius was then priest and catechist in that church, and
supported the high reputation of its school, so as to be styled himself the
young Origen. Among the many works which Pierius left, nothing but some few
fragments have reached us. Photius tells us, that in a book which he wrote upon
St. Luke’s gospel, he proved that the disrespect which is shown to images falls
back upon that which they represent. St. Theonas himself wrote a useful letter
of instruction, how the Christians who lived in the emperor’s court ought to
behave; it was addressed to Lucian, first chamberlain to the Emperor
Dioclesian. St. Theonas died in 300, and was succeeded by St. Peter. St.
Alexander built in that city a church dedicated to God, under the patronage of
St. Theonas.