This info is taken from the Wikipedia entry for Serena Butler..
The fanatical Cult of Serena was founded in 108 B.G. by Rayna Butler (b. 119 B.G), the great-granddaughter of Xavier Harkonnen and Serena's sister Octa Butler. Rayna's father Rikov Butler governed the planet Parmentier (a former Synchronized World recolonized by the League), which was being ravaged by the Omnius Scourge, a catastrophic virus genetically engineered and unleashed by the Thinking Machines to destroy humanity. Having seen her parents succumb to the plague and barely surviving herself, young Rayna began her personal crusade against the machines. Claiming to have had a vision of Serena (possibly a hallucination caused by her illness), Rayna began destroying both electronic and mechanical machines, including innocuous devices and desperately needed medical equipment. The subsequent antitechnology mobs hampered the work and threatened the lives of Mohandas Suk and Raquella Berto-Anirul (granddaughter of Vorian Atreides), doctors who had established the Hospital for Incurable Diseases on Parmentier. Suk and Berto-Anirul barely escaped the planet. A new group known as the Martyrists, who worshipped The Three Martyrs (Serena Butler, Manion the Innocent, and Iblis Ginjo), were instantly taken up by Rayna’s mission. In 88 B.G., the Cult started destroying machines on Salusa Secundus.
Led by Rayna, the Cult of Serena caused more mayhem for humans than the thinking machines. After the Butlerian Jihad, machine destruction spread to the inhabited planets in renewed waves, wiping out most machine-based technology and also the majority of historical documents. Culture based on the production of highly developed machines survived only on Ix and Richese.
Despite inherent double standards (such as the destruction of some technology, but the continuous use of spaceships) within the group, the Cult’s legacy endured. One of the primary commandments in the Orange Catholic Bible, “Thou shall not make a machine in the likeness of a human mind,” is attributed directly to Rayna Butler. Furthermore, the group is responsible for the strict rules banning all thinking machines under pain of death (and sometimes torture).