Mosaic Of Justinian With Guards, Officials, And Clerics, in the church of San Vitale at Ravenna (c. A.D.
547). The Emperor, who briefly reunited Italy to the Eastern Empire, is shown wearing a halo and
carrying a gold vessel at the consecration of the church; the Archbishop Maximian stands at his side.
The barbarian domination made people assertive about Romanitas. In Theoderic's Italy Boethius and
Cassiodorus set about preserving ancient culture and philosophy. Boethius declared his 'fear that many
things which are now known soon will not be'. At Constantinople Priscian wrote a Latin grammar which
long educated the medieval West. Justinian's loudest assertion of Roman values was his code of laws
superseding the Theodosian Code. All imperial edicts not included were declared invalid. In the
Theodosian Code some edicts ('laws of citations') prescribed the legal authorities which could be cited as
argument in court: Papinian, Paulus, Ulpian, Modestinus, Gaius, a majority among them being decisive.
Under the great quaestor Tribonian, Justinian instructed his law commission of professional jurists to
make a digest of the classical authorities, and this huge book remains the main source for our knowledge
of classical Roman law. The way in -which Tribonian's commissioners went about the task of compiling
the Digest has given modern legal historians an unrivalled problem in detection and decoding, to which
the utmost ingenuity has been applied. Justinian also put his name to a textbook of law, Institutiones or