No European country, however, could adopt the code of Theodosian or Justinian in its entirety. In the rapid changes in human life and institutions laws cannot remain stationary, but must advance to meet new conditions. What was therefore adopted by the European countries of this period was not the Roman law, but a new and modern system based upon it, to which the name of the Civil Law came to be applied. The development of this law, like the work of the formation of the Roman Codes, was the work rather of the law schools than of the law making powers of the State. Early in the twelfth century the gloss to the Corpus Juris Civilis was produced at Bologna, and the glosses of the various law professors soon grew to an enormous volume. Finally, a digest of the various earlier glosses was completed by Accursius and his sons, which acquired such reputation that for a time it became accepted as the highest of all legal authority.

The Civil Law took various forms in the different countries, but in all it retained, and has retained down to the present day, a firm foundation of legal rules and conceptions taken from the Roman law principles of the time of the highest development of that wonderful system of jurisprudence.