Recognovit Paulus Krueger
Corpus Iuris Civilis, vol. I )
   As the Digest neared completion, Tribonian and two professors, Theophilus and Dorotheus, made a students' textbook, called the Institutiones or « Elements ». As there were four elements, the manual consisted of four books. The Institutiones are largely based on the Institutiones of Gaius. Two thirds of the Institutiones of Justinian consist of literal quotes from Gaius. The new Institutiones were used as a manual for would-be jurists since 21 November 533 and were given the authority of law on 30 December 533 along with the Digest.