Valentinianism was one of the major Gnostic Christian movements. Founded by Valentinus in the 2nd century AD, its influence spread widely, not just within Rome but also from Northwest Africa to Egypt through to Asia Minor and Syria in the East. Later in the movement's history it broke into an Eastern and a Western school. Disciples of Valentinus continued to be active into the 4th century AD, after the Roman Emperor Theodosius I issued the Edict of Thessalonica (380 AD), which declared Nicene Christianity as the State church of the Roman Empire. The doctrine, practices and beliefs of Valentinus and the Gnostic movement that bore his name were condemned as heretical by proto-orthodox Christian leaders and scholars. Prominent Church Fathers such as Irenaeus of Lyons and Hippolytus of Rome wrote against Gnosticism. Because early church leaders encouraged the destruction of Gnostic texts, most evidence for the Valentinian theory comes from its critics and detractors, most notably Irenaeus, since he was especially concerned with refuting Valentinianism. History Valentinus was born in approximately 100 AD and died in Alexandria circa 180 AD. According to the Christian scholar Epiphanius of Salamis, he was born in Egypt and schooled in Alexandria, where the Gnostic Basilides was teaching. However Clement of Alexandria (c.150c.215), another Christian scholar and teacher, reports that Valentinus was taught by Theudas, a disciple of the apostle Paul. He was reputed to be an extremely eloquent man who possessed a great deal of charisma and had an innate ability to attract people. He went to Rome some time between AD 136 and 140, in the time of Pope Hyginus, and had risen to the peak of his teaching career between AD 150 and 155, during the time of Pius. For some time in the mid-2nd century he was even a prominent and well-respected member of the Catholic community in Rome. At one point during his career he had even hoped to attain the office of bishop, and apparently it was after he was passed over for the position that he broke from the Catholic Church. Valentinus was said to have been a prolific writer; however, the only surviving remains of his work come from quotes that have been transmitted by Clement of Alexandria, Hippolytus and Marcellus of Ancyra. Most scholars also believe that Valentinus wrote the Gospel of Truth, one of the Nag Hammadi texts. Notable Valentinians included Heracleon (fl. ca. 175),