To a special category of technical glossaries belongs a large and important class of works relating to the law-compilations of Justinian. Although the emperor forbade under severe penalties all commentaries ([Greek: hupomnêmata]) on his legislation (_Const. Deo Auctore_, sec. 12; _Const. Tanta_, sec. 21), yet indices ([Greek: indikes]) and references ([Greek: paratitla]), as well as translations ([Greek: ermêneiai kata poda]) and paraphrases ([Greek: hermêneiai eis platos]), were expressly permitted, and lavishly produced. Among the numerous compilers of alphabetically arranged [Greek: lexeis Rhômaïkai] or [Greek: Lateinikai], and [Greek: glôssai nomikai] (glossae nomicae), Cyril and Philoxenus are particularly noted; but the authors of [Greek: paragraphai], or [Greek: sêmeiôseis], whether [Greek: exôthen] or [Greek: esôthen keimenai], are too numerous to mention. A collection of these [Greek: paragraphai tôn palaiôn], combined with [Greek: neai paragraphai] on the revised code called [Greek: ta basilika], was made about the middle of the 12th century by a disciple of Michael Hagiotheodorita. This work is known as the _Glossa ordinaria_ [Greek: tôn basilikôn].[3]
In Italy also, during the period of the Byzantine ascendancy, various glossae (glosae) and scholia on the Justinian code were produced[4]; particularly the Turin gloss (reprinted by Savigny), to which, apart from later additions, a date prior to 1000 is usually assigned. After the total extinction of the Byzantine authority in the West the study of law became one of the free arts, and numerous schools for its cultivation were instituted. Among the earliest of these was that of Bologna, where Pepo (1075) and Irnerius (1100-1118) began to give their expositions. They had a numerous following, who, besides delivering exegetical lectures ("ordinariae" on the _Digest_ and _Code_, "extraordinariae" on the rest of the _Corpus juris civilis_), also wrote Glossae, first interlinear, afterwards marginal.[5] The series of these glossators was closed by Accursius (q.v.) with the compilation known as the _Glossa ordinaria_ or _magistralis_, the authority of which soon became very great, so that ultimately it came to be a recognized maxim, "Quod non agnoscit glossa, non agnoscit curia."[6] For some account of the glossators on the canon law, see CANON LAW.