Schaff, Philip. History of the Christian Church (The Complete Eight Volumes in One). Amazon Kindle Edition, 2014.
Volume 2, Ante-Nicene Christianity A.D. 100-325, “Chapter 11. The Heresies of the Ante-Nicene Age” Sections 112-136, Loc. 17655-18757.
§ 121. Simon Magus and the Simonians.
Simon Magus appears in Acts 8, where he is engaged in sorcery and has a conflict with the apostle Peter (Schaff 2014, Loc. 18133). Schaff finds some debate, even in the first and second centuries, about whether he corresonds with particular figures known to that time. Simon’s conflict with Peter was probably about the year 40. His views that the Gospel would be complemented or managed alongside magical arts classed him as the first of the heretics, as well as a proto-Gnostic (Schaff 2014, Loc. 18142). In later writing, Simon Magus is considered the father of all heretics, where he and Peter frequently square off against one another in different places (Schaff 2014, Loc. 18149).
Schaff observes that the church fathers considred Simon and his followers to have a primitive and crude form of Gnosticism. They did have a central idea of a great power, but it was not well elaborated (Schaff 2014, Loc. 18157). There were some offshoots, which mostly died out by the end of the third century.