The body of the Roman law, compiled by order of Justinian (527-565 A.D.), was intended primarily for the eastern empire; but when, in the year 535, the Emperor conquered the western Goths, who then ruled Italy, he ordered his laws taught in the school of jurisprudence at Rome and practiced in the courts.  I have already remarked that the barbarians who overran Italy allowed the vanquished the right to be judged in most cases by their own code.  But the splendid fabric of the Roman law was too elaborate a system to win the attentive study of a rude people; the Church had its own canons, the people their own ancestral customs; and until the twelfth century no development of the Roman Civil Code took place.  Finally, during the twelfth century, the great school at Bologna renewed the study with vigour, and Italy at the present day derives the basic principles of its civil law from the Corpus of Justinian.  Practically the same story holds true of France,[364] of Spain, and of the Netherlands, all of whom have been influenced particularly by the great jurists of the sixteenth century who were simply carrying further the torch that had been lit so enthusiastically at Bologna in the twelfth century.

As to Germany,[365] when that unhappy country had been separated from France and Italy after the Treaty of Verdun in 843, Carlovingian law and the ancient German law books fell into disuse.  The law again rested on unwritten customs, on the decisions of the judges and their assessors, and on agreements of the interested parties (feudal services and tenures).  Not till the twelfth and thirteenth centuries was any record made of the rules of law which had arisen; many laws of cities on various matters and in various provinces were recorded by public authority; and thus originated the so-called law books of the Middle Ages, the private labours of experienced men, who set forth the legal principles which were recognised in all Germany, or at least in certain parts of it.  There were no law schools as yet, and scientific compilation of German law was not even thought of.  After the University of Bologna had revived the study of Roman law in Italy, the Italian universities attracted the German youth, who on their return would labour to introduce what they had learned.  Their efforts were seconded by the clergy, through the close connection with canon law which was in force in Germany.  German emperors and territorial lords also favoured Roman law because they saw how well suited it was to absolutism; they liked to engage jurists trained in Italy, especially if they were doctors of both canon and Roman law.  Nor did the German people object.  From the fourteenth century many schools of jurisprudence were established on Italian models.

At present, the law of Justinian has only such force as is received by usage or as it has acquired by recognition.  I. The Roman law forms in Germany the principal law in some branches, that is, it is in so far its basis that the German law is only an addition or modification of it.  In other branches it is only supplementary, that is, it is merely subsidiary to the German law.  II.  Only the glossed parts and passages of Justinian’s law collection have binding force in Germany.