What is satanism and when does it date from?

Answer 1

There are numerous types of Satanism. The link above (Satanism 101 site) will give you the Atheistic definition and information about LaVeyan Satanism.

But I have to also point out that there are also Theistic forms of Satanism. Some theistic forms are reverse-Christian, others aren't.

See this site to explore the history on the Theistic side:

http://www.theisticsatanism.com/

Answer 2

The cult of Satan, or Satan worship, is in part a survival of the ancient worship of demons and in part a revolt against Christianity or the church. It rose about the 12th cent. in Europe and reached its culmination in the blasphemous ritual of the Black Mass, a desecration of the Christian rite. The history of early Satanism is obscure. It was revived in the reign of Louis XIV in France and is still practiced by various groups throughout the world, particularly in the United States. One of the largest and most influential Satanic groups is the Church of Satan (1966), founded by Anton LaVey in San Francisco. A splinter group, the Temple of Set (1975), was organized by Michael Aquino. Many Satanic groups, including the ones mentioned, attest that such worship does not necessarily imply evil intentions, but rather an alternative to the repressive morality of many other religious groups. Such groups see no harm in their indulgence in “worldly pleasures” that other religions forbid. Other, more severe brands of Satanism likely exist, although much of the activity pegged as “Satanic” has less to do with the religion than with various forms of sociopathy. Indeed, reliable research has found no evidence indicating the existence of alarming, large-scale Satanic phenomena. An unfortunate mistake is the unfounded—yet common—linkage of minority religious traditions, such as the African-derived voodoo and Santería, with Satanism. See also witchcraft.

Answer 3

Properly speaking, the 1960's. The link given above is pretty darn good, I must say.

Answer 4

http://www.satanism101.com/ Go here.