(born c.190)Bishop of Alexandria. He studied under Origen, and eventually became the head of the catechetical school. In 250 there was a severe persecution under Decius in Alexandria, which Dionysius attempted to flee, but was taken into custody. He was rescued by Christians and remained in hiding in the Libyan desert until the persecution ceased, 251. At this juncture the Novatian schism occurred in which Dionysius supported Cornelius, the rightful pope, and it was largely through his influence that the whole East was unified. During the persecution of Valerian, he was banished, 257, to the desert of Mareotis, returning to Alexandria when toleration was decreed, 260, by Gallienus. Dionysius dealt leniently with the Christians who had lapsed during the persecutions and refused forgiveness to none at the hour of death. He wrote a work on the Apocalypse, which ranks high as biblical criticism.