Short answers, pulled from the story.
The term Satanist emerged during the Reformation and Counter-Reformation, appearing in English and French texts as early as 1559 to describe Anabaptists and other Protestant sects as swarms of Satanists.
Estimates suggest between 40,000 and 60,000 people were executed during the witch trials of the fifteenth to the eighteenth centuries, almost all in Europe, based on the idea of a Satanic conspiracy.
Satanism as a self-declared religion began in 1966 with the founding of the Church of Satan by Anton Szandor LaVey in San Francisco, California.
Theistic Satanism, otherwise referred to as spiritual Satanism or devil worship, is a form of Satanism with the primary belief that Satan is an actual deity or force to revere or worship.
The Temple of Set is an occult left-hand path religious organization founded in 1975 when Michael Aquino, the founder of a Church of Satan Grotto in Louisville, Kentucky, left the church.
The Satanic Temple, based in Salem, Massachusetts and active since 2012, has been called the most prominent satanic organization in terms of both size and public activity, claiming 700,000 members worldwide.