JORDANUS DE NEMORE (fl. ca. 1220), mechanics, mathematics.

Although Jordanus has been justly proclaimed the most important mechanician of the Middle Ages and one of the most significant mathematicians of that period, virtually nothing is known of his life. That he lived and wrote during the first half of the thirteenth century, and perhaps as early as the late twelfth century, is suggested by the inclusion of his works in the Biblionomia, a catalogue of Richard de Fournival's library compiled sometime between 1246 and 1260.1 In all, twelve treatises are ascribed to Jordanus de Nemore, whose name is cited four times in this form.2 Since most of his genuine treatises are included, it seems reasonable to infer that Jordanus' productive career antedated the Biblionomia.

The appellation “Jordanus de Nemore” is also found in a number of thirteenth-century manuscripts of works attributed to Jordanus. The meaning and origin of “de Nemore” are unknown. It could signify “from” or “of Nemus,” a place as yet unidentified (the oft-used alternative “Nemorarius,” frequently associated with Jordanus, is apparently a later derivation from “Nemore”), or it may have derived