UGUCCIONE da PISA. - Medieval decretist and lexicographer, born in Pisa in the first half of the 12th century, died in Ferrara on 30 April 1210.
At the Studium of Bologna, where he obtained his doctorate and then taught canon law from 1178 to 1190, he shone as the most celebrated magister decretorum of his age. Among his disciples was Lothair of the Counts of Segni, the future Pope Innocent III, who always held him in high esteem and consideration, as is evident from the decretal letters he dedicated to and sent him as pope, later collected in the Liber Decretarium of Gregory IX. In 1190 he was appointed bishop of Ferrara. From 1197 to 1201, by papal order, he worked at Nonantola on the reorganization of the famous abbey.
He is the author of a most celebrated Summa Decretorum (still unpublished), composed between 1187 and 1190, the broadest, most original, and at the same time most important work of its kind, which extended his influence as a supreme master throughout the Middle Ages. For causes XXIII-XXVI, which U. left without commentary, the work received several anonymous continuations; the principal one was by John of Dio (c. 1240). U. also composed numerous important glosses on the Decretum, which were later incorporated into the Glossa ordinaria to the Decretum itself.
U. was also a distinguished scholar of grammar and lexicography. In this field, his principal work is the Derivationes (incised), a kind of etymological lexicon, modeled on the similar work of Papias, which, despite the defects of the age, enjoyed great diffusion and authority in the Middle Ages and served as Dante’s dictionary. He also wrote, in the grammatical field, De dubio accentu, the Rosarium, and the Summa artis grammaticae, discovered by Grabmann.