The Severians were a sect of gnostic Encratites

Encratites

The Encratites were an ascetic 2nd century sect of Christians who forbade marriage and counselled abstinence from meat. Eusebius says that Tatian was the author of this heresy...

. Epiphanius

Epiphanius of Salamis

Epiphanius of Salamis was bishop of Salamis at the end of the 4th century. He is considered a saint and a Church Father by both the Eastern Orthodox and Catholic Churches. He gained a reputation as a strong defender of orthodoxy...

 supposes their leader Severus to have preceded Tatian

Tatian

Tatian the Assyrian was an Assyrian early Christian writer and theologian of the 2nd century.Tatian's most influential work is the Diatessaron, a Biblical paraphrase, or "harmony", of the four gospels that became the standard text of the four gospels in the Syriac-speaking churches until the...

 (founder of Encratites) but Eusebius, Theodoret

Theodoret

Theodoret of Cyrus or Cyrrhus was an influential author, theologian, and Christian bishop of Cyrrhus, Syria . He played a pivotal role in many early Byzantine church controversies that led to various ecumenical acts and schisms...

, and Jerome

Jerome

Saint Jerome was a Roman Christian priest, confessor, theologian and historian, and who became a Doctor of the Church. He was the son of Eusebius, of the city of Stridon, which was on the border of Dalmatia and Pannonia...

 make him Tatian's successor. These latter authorities are followed by most ecclesiastical historians, and the silence of Irenaeus

Irenaeus

Saint Irenaeus , was Bishop of Lugdunum in Gaul, then a part of the Roman Empire . He was an early church father and apologist, and his writings were formative in the early development of Christian theology...

 and Hypolitus regarding Severus renders the later date most probable.

Ephiphanius ascribes to the Severians a belief in the well known Gnostic power Ialdaboth

Demiurge

The demiurge is a concept from the Platonic, Neopythagorean, Middle Platonic, and Neoplatonic schools of philosophy for an artisan-like figure responsible for the fashioning and maintenance of the physical universe. The term was subsequently adopted by the Gnostics...

 (Yaldabaoth) who appears in the Ophite

Ophite

Ophite may refer to:*Ophites, an ancient Gnostic sect in Syria and Egypt*A name for verd antique, a type of serpentinite building stone...

 system as the first offspring of Bythus and Ennoia. The Severians held that Ialdaboth was a great ruler of the powers, that from him sprung the Devil

Devil

The Devil is believed in many religions and cultures to be a powerful, supernatural entity that is the personification of evil and the enemy of God and humankind. The nature of the role varies greatly...

: that the Devil being cast down to the earth in the form of the serpent produced the vine, whose snake-like tendrils indicate its origin: that the Devil also created woman and the lower half of man.