Azo of Bologna

The Summa Codicis, and Apparatus ad codicem, collected by his pupil, Alessandro de Santo Aegidio, and amended by Hugolinus and Odofredus, formed a methodical exposition of Roman law.

Azo studied civil law in his native city, Bologna, under the glossator Johannes Bassianus, and was teaching there by 1190 at the latest.

Azo furthermore wrote his “great apparatuses” to the first part of the Digesta, the Digestum vetus, and books 1 through 9 of the Codex, in which he discussed matters more extensively than had previous writers.

Azo also wrote a commentary to the Digest title De regulis iuris as well as a book of distinctions, neither of them printed.

[2] The legal historian Frederic William Maitland edited Select Passages from the Works of Bracton and Azo.