The work of the famous Protestant scholar Geoffrey Barton Russell, Satan, is a continuation of his earlier book, The Devil. The second volume brings the history of the development of this concept in Christian thought up to the 5th century. n. e., when the main directions of the demonological tradition were already formed in general terms. The author primarily analyzes the Christian tradition (an overview of Jewish post-apocalyptic thought is given in a condensed form) and focuses on the Western and Eastern branches of Christianity, including additional research on the views of heretics.