The Corpus Juris Civilis represents the Roman law in the form which it assumed at the close of the ancient period (a thousand years after the decemviral legislation of the Twelve Tables), and through which mainly it has acted upon modern times. It was compiled in the Eastern Roman Empire (the Western ceased in 476 a.d.), under the Emperor Justinian (controversies as to his character), who reigned 527–565 a.d.