Secret organizations have existed in one form or another throughout history, but in the modern world, where television, the Internet and instant communications worldwide have exposed so many hitherto impenetrable networks, the mysterious nature of sects that set themselves apart from normal society holds a special fascination. Many of the secret societies functioning today are of a benign, even charitable nature but some, with roots that may stretch back many centuries, seek the power to fulfill ambitions that could change our way of life for ever. Others have strong and widespread links to organized crime around the world. Their policies and plans that revolve around hatred, violence, murder, political intrigue, sex and magic rituals make their activities profoundly disturbing, and their corruption, barbarism and brutality have led to some of the most heinous crimes ever committed. The Most Evil Secret Societies In History examines fifteen of the most notorious groups the world has ever seen, from the Hashishim killers in the Middle East at the time of the Crusades, who gave their name to the word 'assassin', to the Solar Temple international suicide sect of the 1990s. One secret society which has gained a unique notoriety in recent years is the Illuminati. The name has been adopted by a number of coteries over the centuries, the last of which is thought to have died out in the eighteenth century, although some conspiracy theorists continue to blame the Illuminati for having influenced almost every major world event, from the French Revolution to the 9/11 atrocities. While the continued existence of the Illuminati remains a subject of debate, other secret associations, such as the American Ku Klux Klan, continue to cast their shadow over civilization, pursuing an agenda that runs contrary to the beliefs of the majority of the population and proving that, even in the twenty-first century, clandestine organizations are still at work in our midst.