With the passage of time, and against his will, he was ordained to the holy priesthood. Later, at the insistence of the Patriarch, he was made an igumen. Serving in this rank, he tonsured his own father into monasticism. Saint Anthony was distinguished by his mercy, by his love and concern for the destitute, and he provided generous help to them.
Elevated to the Patriarchal throne at Constantinople in 893, Saint Anthony intensified his care for the destitute, and especially for their spiritual condition. With the assistance of the emperor Leo the Wise, Patriarch Anthony did much good for the Church, and encouraged piety in the people. He also built a monastery over the relics of Saint Kallia (February 12). Despite being stooped over with age, he went around all the churches, fulfilling the command of the Savior to be the servant of all the brethren.
In the year 895, advanced in age, Saint Anthony went peacefully to the Lord.