He was made Archbishop of Alexandria through the intervention of Florus, Commander of the city, provoking the displeasure of some people, who, lead astray by the Monophysites, elected as Archbishop of Alexandria Timotheos Ailuros, who was later exiled by Emperor Leon I. Bloody encounters ensued between the followers of the two Hierarchs, during which Proterius was murdered. He is honoured as a Saint of the Church.
