It is not, however, for Saint Sophia that Justinian is chiefly remembered but for the _Corpus Juris Civilis_, literally ‘the body of Civil Law’, that he published in order that his subjects might know what the Roman law really was. The _Corpus Juris Civilis_ consisted of three parts--the ‘Code’, a collection of decrees made by various emperors; next the ‘Digest’, the decisions of eminent lawyers; and thirdly the ‘Institutes’, an explanation of the principles of Roman law. ‘After thirteen centuries,’ says a modern writer, ‘it stands unsurpassed as a treasury of legal knowledge;’ and all through the Middle Ages men were to look to it for inspiration. Thus it was on the _Corpus Juris Civilis_ that ecclesiastical lawyers based the Canon law that gave to the Pope an emperor’s power over the Church.
Justinian worked for the progress of the world when he codified Roman law. It was unfortunate that military ambition led him to exhaust his treasury and overtax his subjects, in order that he might establish his rule over the whole of Europe like Theodosius and Constantine. Besides carrying on an almost continuous war with the King of Persia, he sent an army and fleet under an able general, Belisarius, to fight against the Vandals in North Africa; and so successful was this campaign that Justinian became master of the whole coast-line, and even of a part of southern Spain. This gave him command of the Mediterranean, and he at once determined to overthrow the feeble descendants of Theodoric, and to restore the imperial dominion over Italy in deed, not as it had been from the time of Odoacer merely in name.
The task was not easy, for the Italians, as we have noticed, did not love the Greeks, while the Goths fought bravely for independence. At length, in the year 555, after nineteen campaigns, Narses, an Armenian who was at the head of Justinian’s forces, succeeded in crushing the Barbarians and established his rule at Ravenna, from which city, under the title of _Exarch_, he controlled the whole peninsula.
Narses’ triumph had been in a great measure due to a German tribe, ‘The Lombards’, whose hosts he had enrolled under the imperial banner. These Lombards, _Longobardi_ or ‘Long Beards’ as the name originally stood, had migrated from the banks of the Elbe to the basin of the Danube, and there, looking about them for a warlike outlet for their energies, were quite as willing to invade Italy at Justinian’s command as to go on any other campaign that promised to be profitable.