Carpocrates - Wikipedia: The founder of an early Gnostic sect from the first half of the second century.
Cerinthus - Wikipedia: The leader of a late first-century or early 2nd century sect, an offshoot of the Ebionites yet similar to Gnosticism.
Marcion of Sinope - Wikipedia: A major 2nd century Early Christian theologian, founder of what would later be called Marcionism.
Valentinus - Wikipedia: The best known and for a time most successful Early Christian Gnostic theologian.