A pupil of Ulpian (q.v.), he was the last of the classical jurists and enjoyed considerable fame, although his works lack originality. He was *praefectus vigilum* and is recorded in 239 as having the *ius respondendi*; he is one of the five jurists cited in the Law of Citations (q.v.).
Among his works, all of an elementary nature, intended for teaching and practice, are 12 books of *Pandectae*, 10 of *Regulae*, 9 of *Differentiae*, and 19 of *Responsa*. He also wrote many *libri singulares* (on wills, manumissions, marriage rites, etc.); six books *De excusationibus* in Greek are also attributed to him.
BIBL.: P. Krüger, *Geschichte der Quellen und Literatur des röm. Rechts*, 2nd ed., Leipzig 1912, pp. 253 ff.; P. de Francisci, *Storia del diritto romano*, II, 1, Milan 1938, pp. 517 ff. Rodolfo Danieli