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. Clement of Alexandria (c.150 – c.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.
Valentinus is said to have been a very successful teacher, and 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), Ptolemy, Florinus, Axionicus and Theodotus.