Infidelium

Infidelium is a Latin term that translates as “of the infidels” or “belonging to the unbelievers.” It appears primarily in historical, theological, and literary contexts where Latin served as the scholarly lingua franca. In medieval and early‑modern Catholic writings, the word was often used to distinguish non‑Christians from the faithful, especially in papal bulls, crusade propaganda, and theological treatises. Phrases such as regnum infidelium (“the kingdom of the infidels”) and terra infidelium (“the land of the infidels”) labeled territories under Muslim or pagan control and justified missionary or military activity.

The term also titles several notable works. The 1586 treatise *De ludo infidelium* examines perceived errors of non‑Christian religions, while the 19th‑century historical study *Regnum Infidelium* by French historian Jean‑Louis Gassendi surveys the political organization of non‑Christian societies during the Crusades. In literature, the phrase appears in Dante’s *Divine Comedy* and in the writings of Erasmus, who employed it to critique religious intolerance.

In contemporary usage, infidelium survives chiefly as a scholarly reference or as a lexical example in studies of Latin etymology and ecclesiastical language. It is occasionally invoked in modern theological discourse to discuss concepts of religious otherness, though most modern authors prefer more neutral terminology such as “non‑believers” or “people of other faiths.”