(Or Guarnerius), jurist and founder of a school of glossators; b. Bologna, c. 1050; d. there, c. 1130. Little is known about this famous jurist's life and works. At the turn of the century his influence on medieval jurisprudence received attention justly deserved. At about age 20 he taught didactics and rhetoric at Bologna; and, encouraged by Countess Matilda of Tuscany, he devoted himself to the study of jurisprudence, principally through private studies. In 1084 he founded a school of jurisprudence at Bologna that gave great impulse to juridical studies throughout Europe. He was the first to introduce marginal glosses to expound Roman law, a custom that many followed. He defended the rights of Henry V in a papal election and the election of antipope Gregory VIII. Most of his works are not extant. His principal work, Summa codicis, is the first medieval system of Roman jurisprudence. This work was edited by Fitting (Berlin 1894). Quaestiones de juris subtilitatibus is generally ascribed to him. It, too, was edited by Fitting (Berlin 1894).
Bibliography: e. besta, L'opera d'Irnerio: Contributo alla storia del diritto italiano, 2 v. (Turin 1896). h. h. fitting, Die Anfänge der Rechtsschule zu Bologna (Berlin 1888); "Die Summa Codicis und die Quaestiones des I.," Zeitschrift der Savigny-Stiftung für Rechtsgeschichte, Romanistische Abteilung 17 (1896) 1–96. f. k. v. savigny, Geschichte des römischen Rechts im Mittelalter 4:9–67, 447–470. f. schupfer, La scuola di Roma e la questione irneriana (Rome 1898). f. patetta, La Summa Codicis e la quaestiones falsamente attribite ad Irnerio (Turin I897). l. chiappelli, "I. secondo la nuova critica storica," Rivista storica italiana 11 (1894) 607–628. Ius romanum medii aevi (Milan 1961–) pt. 1. a. berger, Encyclopedic Dictionary of Roman Law (Trans. Amer. Philos. Soc. NS 43.2; Philadelphia 1953) 516. h. kantorowicz and w. w. buckland, Studies in the Glossators of the Roman Law (Cambridge, Eng. 1938).
[t. d. dougherty]