On the Heavenly Hierarchy

The Holy Martyr Dionysius the Areopagite lived in the 1st century AD in Athens. He was elected a member of the Areopagus and became a companion of the Apostle Paul, who appointed him bishop of Athens. He witnessed a solar eclipse at the moment of the crucifixion of the Lord Jesus Christ and was present at the burial of the Most Holy Theotokos. The book "On the Heavenly Hierarchy" contains an angelic classification through triads according to their closeness to God. Seraphim, Cherubim, and Thrones belong to the highest hierarchy; Dominions, Virtues, and Powers to the middle; and Principalities, Archangels, and Angels to the lowest. This division did not correspond to the conception of the world of angels in the Old Testament, but it was accepted by some later theologians, among whom were Thomas Aquinas, Gregory Palamas, and others.