Early Christians considered Simon Magus the founder of Gnosticism.  Born in Samaria, Simon Magus was baptized by Phillip but later offered the apostles money to receive the power of the Holy Spirit (Acts 8:9-24).  Following this account in Acts, he began to deceive his own people, teaching that he was God in the flesh.  Emperor Claudius Caesar eventually built a statue in his honor, and many people worshipped him as a god.  Although Simon Magus’ sphere of influence was limited and faded quickly, the early Christian writers considered him the founder of Gnosticism.  Read more about Gnosticism here.