On January 26, 1475 printer Peter Schöffer of Mainz issued the first edition of the Codex Justinianus with the commentary of Franciscus Accursius. This is the first part of the Corpus Juris Civilis (Body of Civil Law) originally issued from Contantinople from 529 to 534 by the Byzantine Emperor Justinian I.
"Justinian's Corpus Juris Civilis was lost in the West, where it was scarcely needed in the primitive conditions that followed the collapse of Odoacer's sub-Roman kingdom. Historians disagree on the precise way it was recovered in Northern Italy about 1070: perhaps it was waiting unneeded and unnoticed in a library until the legal studies that were undertaken on behalf of papal authority that was central to the Gregorian Reform of Pope Gregory VII led to its accidental rediscovery. Aside from the Littera Florentina, a 6th-century codex of the Pandects that was jealously preserved at Pisa, since 1406 at Florence, there may have been other manuscript sources for the text that began to be taught at Bologna, by Pepo and then by Irnerius, whose technique was to read a passage aloud, which permitted his students to copy it, then to deliver an excursus explaining and illuminating Justinian's text, in the form of glosses. Irmerius' pupils, the "Four Doctors" were among the first of the "Glossators" who established the curriculum of Roman law."
"The merchant classes of Italian communes required law with a concept of equity and which covered situations inherent in urban life better than the primitive Germanic oral traditions. The provenance of the Code appealed to scholars who saw in the Holy Roman Empire a revival of venerable precedents from the classical heritage. The new class of lawyers staffed the bureaucracies that were beginning to be required by the princes of Europe. The University of Bologna, where Justinian's Code was first taught, remained the dominant center for the study of law through the High Middle Ages."