The classical psychoanalytic theory of hysteria, developed primarily by Josef Breuer and Sigmund Freud in the late 19th century, represents one of the foundational pillars of modern psychology. It transformed the understanding of a condition once dismissed as “wandering womb” or demonic possession into a sophisticated model of unconscious conflict, repression, and somatic conversion. Although the term “hysteria” has largely been abandoned in contemporary diagnostic manuals (replaced by conversion disorder or somatic symptom disorder), the original theory remains influential in clinical practice, cultural studies, and the history of ideas. This essay outlines the historical context, core concepts, key mechanisms, landmark…