Saint Eulogius of Alexandria was Greek Patriarch of that see (Eulogius I) from 580 to 608. He is regarded as a saint

Saint

A saint is a holy person. In various religions, saints are people who are believed to have exceptional holiness.In Christian usage, "saint" refers to any believer who is "in Christ", and in whom Christ dwells, whether in heaven or in earth...

, with a feast day of September 13.

He was a successful combatant of the heretical errors then current in Egypt, notably the various phases of Monophysitism

Monophysitism

Monophysitism , or Monophysiticism, is the Christological position that Jesus Christ has only one nature, his humanity being absorbed by his Deity...

. He was a warm friend of Pope St. Gregory the Great, who corresponded with him, and received from that pope many flattering expressions of esteem and admiration.

St. Eulogius refuted the Novatians, some communities of which ancient sect still existed in his diocese, and vindicated the hypostatic union of the two natures in Christ, against both Nestorius

Nestorius

Nestorius was Archbishop of Constantinople from 10 April 428 to 22 June 431.Drawing on his studies at the School of Antioch, his teachings, which included a rejection of the long-used title of Theotokos for the Virgin Mary, brought him into conflict with other prominent churchmen of the time,...

 and Eutyches

Eutyches

Eutyches was a presbyter and archimandrite at Constantinople. He first came to notice in 431 at the First Council of Ephesus, for his vehement opposition to the teachings of Nestorius; his condemnation of Nestorianism as heresy precipitated his being denounced as a heretic...

. Cardinal Baronius says that Gregory wished Eulogius to survive him, recognizing in him the voice of truth.

It has been rightly said that he restored for a brief period to the Church of Alexandria that life and youthful vigour characteristic of those churches only which remain closely united to Rome.

Besides the above works and a commentary against various sects of Monophysites (Severians

Severians

The Severians or Severyans or Siverians were a tribe or tribal union of early East Slavs occupying areas to the east of the middle Dnieper river around the rivers Desna, Sejm and Sula on the territory of the archaeological Romny culture....

, Theodosians

Theodosians

Theodosians can refer to:*The Theodosian dynasty of Roman EmperorsIn Christianity:*The Severians of Alexandria*The Corrupticolæ, supporters of Eutychianism in the patriarchate of Alexandria...

, Cainites

Cainites

The Cainites, or Cainians, were a Gnostic and Antinomian sect who were known to worship Cain as the first victim of the Demiurge Jehovah, the deity of the Tanakh , who was identified by many groups of gnostics as evil...

 and Acephali

Acephali

Acephali is a term applied to several sects as having no head or leader....

) he left eleven discourses in defence of Pope Leo I

Pope Leo I

Pope Leo I was pope from September 29, 440 to his death.He was an Italian aristocrat, and is the first pope of the Catholic Church to have been called "the Great". He is perhaps best known for having met Attila the Hun in 452, persuading him to turn back from his invasion of Italy...

 and the Council of Chalcedon

Council of Chalcedon

The Council of Chalcedon was a church council held from 8 October to 1 November, 451 AD, at Chalcedon , on the Asian side of the Bosporus. The council marked a significant turning point in the Christological debates that led to the separation of the church of the Eastern Roman Empire in the 5th...

, also a work against the Agnoetae

Agnoetae

Agnoetae was a general name given to those heretical sects which in one form or another denied the divine omniscience either of the incarnate Christ or of God the Father....

, submitted by him before publication to Pope Gregory I, who after some observations authorized it unchanged. With exception of one sermon and a few fragments, all the writings of St. Eulogius have perished.