One may say that these codes carried on processes of decline from the full creative genius of Roman jurisprudence, which had irrevocably set in under the Empire in the fourth and fifth centuries. The decline lay in a weakening of the intellectual power devoted to the law and its development. The living growth of the praetorian edict had long since come to an end; and now a waning jurisprudential intelligence first ceased to advance the development of law, and then failed to save from desuetude the achieved jurisprudence of the past. So the jurisprudential and juridical elements (_jus_) fell away from the law, and the imperial constitutions (_leges_) remained the sole legal vehicle and means of amendment. The need of codification was felt, and that preserving and eliminating process was entered upon. Roman codification never became a reformulation. The Roman _Codex_ was a collection of existing constitutions. A certain jurist (“Gregorianus”) made an orderly and comprehensive collection of such as early as the close of Diocletian’s reign; it was supplemented by the work of another jurist (“Hermogenianus”) in the time of Constantine. Each compilation was the work of a private person, who, without authority to restate, could but compile the imperial constitutions. The same method was adopted by the later codifications, which were made and promulgated under imperial decree. There were two which were to be of supreme importance for the legal future of western Europe, the Theodosian Code and the legislation of Justinian. The former was promulgated in 438 by Theodosius II. and Valentinianus. The emperors formally announce that “in imitation (_ad similitudinem_) of the Code of Gregorianus and Hermogenianus we have decreed that all the Constitutions should be collected” which have been promulgated by Constantine and his successors, including ourselves.[356] So the Theodosian Code contains many laws of the emperors who decreed it.[357] It was thus a compilation of imperial constitutions already in existence, or decreed from year to year while the codification was in process (429-438). Every constitution is given in the words of its original announcement, and with the name of the emperor. Evidently this code was not a revision of the law.