author
Jacobus X
A shadowy pseudonymous author, Jacobus X is best known for sensational anthropological and sexual literature that circulated privately in the late 19th century. The name is tied to books that mixed travel-writing poses, taboo subjects, and editorial mystery.
1 Audiobook
Discipline in School and Cloister
by Jacobus X
About the author
Jacobus X is generally presented as the author of works such as Untrodden Fields of Anthropology and Crossways of Sex. Modern library and archive records consistently treat the name as a pseudonym rather than a clearly documented personal identity.
Because the historical record is thin, most reliable summaries focus on the books themselves: privately issued, controversial for their time, and often framed as medical, anthropological, or travel-related studies of sexuality and custom. The aura of secrecy around the name helped give these works a lasting underground reputation.
Some later scholarship links the pseudonym to another identity, but the attribution is not simple enough to state as settled fact here. In short, Jacobus X remains more notable as a literary mask attached to notorious fin-de-siècle texts than as a fully known biographical figure.