The H. P. Lovecraft Historical Society. The H.P. Lovecraft Archive. Dictionnaire Infernal. The Dictionnaire Infernal (English: Infernal Dictionary) is a book on demonology, organised in hellish hierarchies.
It was written by Jacques Auguste Simon Collin de Plancy and first published in 1818. There were several editions of the book; perhaps the most famous is the 1863 edition, which included sixty-nine illustrations by Louis Le Breton depicting the appearances of several of the demons. Many but not all of these images were later used in S. L. MacGregor Mathers's edition of The Lesser Key of Solomon.