See the first Novel of Theodosius, by which he ratifies and communicates (A.D. 438) the Theodosian Code. About 40 years before that time the unity of legislation had been proved by an exception. The Jews, who were numerous in the cities of Apulia and Calabria, produced a law of the East to justify their exemption from municipal offices (Cod. Theod. 1. xvi. tit. viii. leg. 13); and the Western emperor was obliged to invalidate, by a special edict, the law,
quam constat meis partibus esse damnosam. Cod. Theod. 1. xi.
[xii.] tit. i. leg. 158.