Satanism is a group of ideological and philosophical beliefs based on Satan. Contemporary religious practice of Satanism began with Anton LaVey's founding of the Church of Satan in 1966, although a few historical precedents exist. Prior to the public practice, Satanism existed primarily as an accusation by various Christian groups toward perceived ideological opponents, rather than a self-identity. Satanism, and the concept of Satan, has also been used by artists and entertainers for symbolic expression.
Accusations that various groups have been practicing Satanism have been made throughout much of Christian history. During the Middle Ages, the Inquisition attached to the Roman Catholic Church alleged that various heretical Christian sects and groups, such as the Knights Templar and the Cathars, performed secret Satanic rituals. In the subsequent Early Modern period, belief in a widespread Satanic conspiracy of witches resulted in mass trials of alleged witches across Europe and the North American colonies. Accusations that Satanic conspiracies were active, and behind events such as Protestantism (and conversely, the Protestant claim that the Pope was the Antichrist) and the French Revolution continued to be made in Christendom during the eighteenth to the twentieth century.
The idea of a vast Satanic conspiracy reached new heights with the influential Taxil hoax of France in the 1890s, which claimed that Freemasonry worshiped Satan, Lucifer, and Baphomet in their rituals. In the 1980s and 1990s, the Satanic ritual abuse hysteria (commonly referred to as the "Satanic Panic") spread through the United States and United Kingdom, amid fears that groups of Satanists were regularly sexually abusing and murdering children in their rites. In most of these cases, there is no corroborating evidence that any of those accused of Satanism were actually practitioners of a Satanic religion or guilty of the allegations leveled at them. For a very long time since the founding of Christianity, many ideologies and religious belief systems such as Judaism, Islam, Communism, Socialism, Nazism, Fascism, Hinduism, Sihkism, Paganism, Buddhism, Atheism, Liberalism, and even various denominations of Christianity, were accused of Devil worship and Satanic behavior.
Since the 19th century, various small religious groups have emerged that identify as Satanists or use Satanic iconography. Satanist groups that appeared after the 1960s are widely diverse, but two major trends are theistic Satanism (also known as devil worship) and atheistic Satanism. Theistic Satanists venerate Satan as a supernatural deity, viewing him not as omnipotent but rather as a patriarch. In contrast, atheistic Satanists regard Satan as merely a symbol of certain human traits.
Contemporary religious Satanism is predominantly an American phenomenon, the ideas spreading elsewhere with the effects of globalization and the Internet. The Internet spreads awareness of other Satanists, and is also the main battleground for Satanist disputes. Satanism started to reach Central and Eastern Europe in the 1990s, in time with the fall of the Soviet Union, and most noticeably in Poland and Lithuania, predominantly Roman Catholic countries.