Bertrand du Guesclin
Never in French history was this particle proof of nobility. The nobleman was always designated an "escuyer" ("dapifer" in Latin, for 'squire') or, better, a "chevalier" ("equites" in Latin, for 'knight'). Only knights could be designated by the spoken style "monseigneur" or "messire" ("dominus" in Latin, for 'sir'), as, for example, "monseigneur Bertrand du Guesclin, chevalier" (in English form, 'Sir Bertrand du Guesclin, knight').