List of Patriarchs of Alexandria in the context of "Dionysius of Alexandria"

Achillas was the 18th Patriarch of Alexandria, reigning from 312 to 313.

He was born in Alexandria, Egypt, and was renowned for his knowledge and piety; this was why Pope Theonas had ordained him priest and appointed him head of the Catechetical School of Alexandria upon the departure of Pierius. He was apparently very highly thought of for his work in Greek philosophy and theological science, as Pope Athanasius later described him by the honorific "Achillas the Great".

Alexander I of Alexandria (Koine Greek: Ἀλέξανδρος, Aléxandros) was the 19th Patriarch of Alexandria. During his patriarchate, he dealt with a number of issues facing the Church in that day. These included the dating of Easter, the actions of Meletius of Lycopolis, and the issue of greatest substance, Arianism. He was the leader of the opposition to Arianism at the First Council of Nicaea. He also mentored his successor, Athanasius of Alexandria, who would become one of the Church Fathers. He is regarded as a Pope by the Coptic Orthodox Church but not by the Catholic Church.