"Secret Societies of the Middle Ages" by Thomas Keightley is a historical account written in the 19th century. The book delves into the origins and characteristics of secret societies that emerged during the Middle Ages, focusing on groups such as the Assassins, the Knights Templar, and the secret tribunals of Westphalia. Keightley's work aims to offer a comprehensive exploration of these societies, revealing their political, social, and religious implications. The opening of the book introduces the concept of secret societies as a response to the retention of knowledge by select individuals in an environment of general ignorance. Keightley discusses how these groups formed as a means of protecting knowledge and facilitating covert gatherings for political discourse and reform. He hints at the socio-political ramifications of such societies, noting that their clandestine nature often invokes suspicion, leading to misrepresentation and persecution by governing powers. The foundation for understanding the subsequent chapters, which detail specific societies and their historical contexts, is firmly established in this introduction. (This is an automatically generated summary.)