In form, the ius commune was largely nonstatutory it was found largely in the cases, where judges sought out and applied this amalgam of doctrinal principles refined by academics and by jurists to the legal dispute before them. The ius commune, however, was not a static body of doctrine by the nineteenth century it was imbued with humanistic principles of the fifteenth century and natural law thinking of the late seventeenth century. The ius commune could claim its roots in the Roman law of Justinian, as interpreted and expanded by the medieval Italian glossators and commentators, and as influenced by Germanic customary law.
To the extent that it comprised a body of substantive law, the legal principles that obtained were of mixed origin. Prior to the movement for the codification of Continental law in the nineteenth century, of which the Napoleonic Code is the most prominent example, Continental legal systems were based largely on a system of law known as the ius commune.
