(codex), a collection of the laws and constitutions of the Roman emperors, made by order of Justinian. The word comes from the Latin codex, "a paper book;" so called a codicilus, or caudicibus arborum, "the trunks of trees;" the bark whereof being stripped off, served the ancients to write their books on.

The code is accounted the second volume of the civil law, and contains twelve books; the matter of which is nearly the same with that of the digests, especially the first eight books: but the style is neither so pure, nor the method so accurate, as that of the digests; and it determines matters of daily use, whereas the digests discuss the more abstruse and subtle questions of the law, giving the various opinions of the ancient lawyers. Although Justinian's code is distinguished by the appellation of code, by way of eminence, yet there were codes before his time; such were, 1. The Gregorian code, and Hermogenean code; collections of the Roman laws, made by two famous lawyers, Gregorius and Hermogenes, which included the constitutions of the emperors from Adrian to Diocletian and Maximinus. 2. The Theodosian code, comprised in 16 books, formed out of the constitutions of the emperors from Constantine the Great to Theodosius the Younger: this was observed almost over all the west, till it was abrogated by the Justinian code.

There are also several later codes, particularly the ancient Gothic, and those of the French kings; as the code of Euricid, code-Lewis, code-Henry, code-Marmande, code des Eaux, &c.; and the present king of Prussia has lately published a code, which comprises the laws of his kingdom in a very small volume.