Justinian also appointed Tribonian to high offices in the imperial administration, such as magister officiorum and quaestor sacri palatii, but at the beginning of the Nika riots he was forced to dismiss him on charges made by his enemies.

[12] In 528, before he was appointed quaestor, Tribonian was named by Justinian as one of the commissioners charged with preparing the new imperial legal code, the Codex Justinianeus, which subsequently was issued on April 7, 529.

[13] In 530, after Tribonian had become quaestor, it was natural for Justinian to put him in charge of the next major law reform project: compiling and harmonizing the writings of classical Roman jurists.

[14] During the same period, Tribonian also was charged with carrying out another aspect of Justinian's reforms in legal education and codification — creating a textbook for first-year law students by updating the Institutes of Gaius.

[16] In 532, Tribonian was removed as quaestor due to the charges of corruption made by his enemies during the Nika riots, but he continued to work on the codification.