Timothy Aelurus began his career as a [[monk]] in Alexandria under Patr. [[Dioscorus of Alexandria|Dioscorus]], rising to be [[ordination|ordained]] a [[priest]]. After Dioscorus was [[deposition|deposed]] as Patriarch of Alexandria at the [[Fourth Ecumenical Council|Council of Chalcedon]] and was succeeded by Patr. Proterius, Timothy was himself deposed and exiled to Libya. After the death of emperor Marcian, Timothy returned to Alexandria in January 457 and began a practice of "creeping" among the cells of some monks at night, addressing them by name and saying "i am an [[Angels|angel]], sent to warn you to break off [[communion]] with Proterius and choose Timothy as bishop". Through these acts he acquired the epithet ''Aelurus'', in Greek Αίλουρος - cat.
With a group of compatriots, Timothy took possession of the main [[church]] during the latter part of the [[Great Lent]] and then by two [[bishop]]s, who had been deposed and exiled by Patr. Proterius and his [[synod]], was [[consecration of a bishop|consecrated]] and then self-[[enthronement|enthroned]] himself while Proterius was with his [[clergy]] at his residence. After, quickly performing many episcopal acts, he was exiled by the "dux" Dionysius. Apparently in revenge, his supporters hunted down Patr. Proterius in the [[baptistry]] and murdered him.