Answer

Justinian I, ruling from 527–565 AD, commissioned the legal scholar Tribonian to compile and systematize centuries of Roman law into the Corpus Juris Civilis. This monumental work consisted of the Codex, Digest, Institutes, and Novels, and became the foundation of legal systems across medieval Europe and many modern nations. Theodosius II had earlier produced the Theodosian Code, making him a plausible distractor, but it was Justinian's compilation that proved far more comprehensive and enduring.