The Historical Illuminatus Chronicles is a series of three novels by Robert Anton Wilson written after his highly successful The Illuminatus! Trilogy and his 1981 Masks of the Illuminati. His co-author from the first trilogy, Robert Shea, was not involved in this series, providing only a praising blurb.

It is composed of three books: The Earth Will Shake (1982), The Widow's Son (1985) and Nature's God (1991). A fourth book, The World Turned Upside Down, was promised at the end of Nature's God but was never written; Wilson also had stated he intended the Chronicles to be a pentalogy. His death in 2007 left the series as a trilogy, incomplete. There is an audiobook of the first novel read by Scott Crisp.

It concerns the adventures of Sigismundo Celine, an ancestor of the Hagbard Celine character from the Illuminatus! Trilogy, as he blunders through Europe and America during the Enlightenment, constantly fighting to escape becoming a part of history.

In the first book, Sigismundo is an adolescent in Naples, Italy, where his uncle introduces him to the teaching of the Freemasons. In the second book Sigismundo has been banished from Naples because of a lovers' duel. He lives in Paris and is taken captive twice. The first time he is imprisoned in the Bastille, from which he escapes using Masonic techniques of concentration to help distract himself from the pain involved in climbing down from his tower. The second time Sigismundo is imprisoned by a more mysterious group of captors, who seek to convince him that he is a descendant of Jesus Christ. In the third book, Sigismundo finds himself in further exile, in the wilderness of North America.

They have been with us all through history: The "Invisible College" of wisdom, and their adversaries. The history of the world is their story: a conspiracy as vast and all-encompassing as the riddle of time itself.In Naples, Italy, in 1764, a young aristocrat is about to stumble onto one piece of the great pattern. Through a heartless murder and his passion for the beautiful daughter of his enemy, young Sigismundo Celine uncovers the mystery of the Rossi brigade, former M.A.F.I.A. assassins, and the secret agenda of the dreaded Inquisition.In the wind of the raging social storm that will soon tear through Europe and America with the flame of revolution, Sigismundo begins his journey of discovery, joined by the boy Mozart, Dr. Frankenstein, Casanova the spy, lover and magician . . . and a mysterious violet-eyed assassin who calls him "brother." Join him. The journey has just begun."Against the epic backdrop of the French and American revolutions, the inimitable RAW lays bare the secret history of the Enlightenment, while almost casually re-inventing the historical novel in the process. The result is a heady, psychedelic brew of satire, intrigue, magic, high adventure and life-changing philosophy, seasoned with the wry, compassionate humanism which is Wilson's trademark. Astonishing and unforgettable." – Grant Morrison, New York Times best-selling author, Comics Legend, Chaos Magician, creator of The Invisibles and other great graphic novels"Devilish . . . I loved it!" – Greil Marcus, Rolling Stone"Hilarious and multidimensional." — L.A. Times