Thus the Greeks left to history the example that independent and Sovereign States can live, and are in reality compelled to live, in a community which provides a law for the international relations of the member-States, provided that there exist some common interests and aims which bind these States together. It is very often maintained that this kind of International Law of the Greek States could in no way be compared with our modern International Law, as the Greeks did not consider their international rules as legally, but as religiously binding only. We must, however, not forget that the Greeks never made the same distinction between law, religion, and morality which the modern world makes. The fact itself remains unshaken that the Greek States set an example to the future that independent States can live in a community in which their international regulations are governed by certain rules and customs based on the common consent of the members of that community.
The Romans.
§ 40. Totally different again from the Greek contribution to a future International Law is that of the Romans. As far back as their history goes, the Romans had a special set of twenty priests, the so-called fetiales, for the management of functions regarding their relations with foreign nations. In fulfilling their functions the fetiales did not apply a purely secular but a divine and holy law, a jus sacrale, the so-called jus fetiale. The fetiales were employed when war was declared or peace was made, when treaties of friendship or of alliance were concluded, when the Romans had an international claim before a foreign State, or vice versa.
According to Roman Law the relations of the Romans with a foreign State depended upon the fact whether or not there existed a treaty of friendship between Rome and the respective State. In case no such treaty was in existence, persons or goods coming from the foreign land into the land of the Romans, and likewise persons and goods going from the land of the Romans into the foreign land, enjoyed no legal protection whatever. Such persons could be made slaves, and such goods could be seized, and became the property of the captor. Should such an enslaved person ever come back to his country, he was at once considered a free man again according to the so-called jus postliminii. An exception was made as regards ambassadors. They were always considered inviolable, and whoever violated them was handed over to the home State of those ambassadors to be punished according to discretion.
Different were the relations when a treaty of friendship existed. Persons and goods coming from one country into the other stood then under legal protection. So many foreigners came in the process of time to Rome that a whole system of law sprang up regarding these foreigners and their relations with Roman citizens, the so-called jus gentium in contradistinction to the jus civile. And a special magistrate, the praetor peregrinus, was nominated for the administration of that law. Of such treaties with foreign nations there were three different kinds, namely, of friendship (amicitia), of hospitality (hospitium), or of alliance (foedus). I do not propose to go into details about them. It suffices to remark that, although the treaties were concluded without any such provision, notice of termination could be given. Very often these treaties used to contain a provision according to which future controversies could be settled by arbitration of the so-called recuperatores.
Very precise legal rules existed as regards war and peace. Roman law considered war a legal institution. There were four different just reasons for war, namely: (1) Violation of the Roman dominion; (2) violation of ambassadors; (3) violation of treaties; (4) support given during war to an opponent by a hitherto friendly State. But even in such cases war was only justified if satisfaction was not given by the foreign State. Four fetiales used to be sent as ambassadors to the foreign State from which satisfaction was asked. If such satisfaction was refused, war was formally declared by one of the fetiales throwing a lance from the Roman frontier into the foreign land. For warfare itself no legal rules existed, but discretion only, and there are examples enough of great cruelty on the part of the Romans. Legal rules existed, however, for the end of war. War could be ended, first, through a treaty of peace, which was then always a treaty of friendship. War could, secondly, be ended by surrender (deditio). Such surrender spared the enemy their lives and property. War could, thirdly and lastly, be ended through conquest of the enemy's country (occupatio). It was in this case that the Romans could act according to discretion with the lives and the property of the enemy.
From this sketch of their rules concerning external relations, it becomes apparent that the Romans gave to the future the example of a State with legal rules for its foreign relations. As the legal people par excellence, the Romans could not leave their international relations without legal treatment. And though this legal treatment can in no way be compared to modern International Law, yet it constitutes a contribution to the Law of Nations of the future, in so far as its example furnished many arguments to those to whose efforts we owe the very existence of our modern Law of Nations.
No need for a Law of Nations during the Middle Ages.
§ 41. The Roman Empire gradually absorbed nearly the whole civilised ancient world, so far as it was known to the Romans. They hardly knew of any independent civilised States outside the borders of their empire. There was, therefore, neither room nor need for an International Law as long as this empire existed. It is true that at the borders of this world-empire there were always wars, but these wars gave opportunity for the practice of a few rules and usages only. And matters did not change when under Constantine the Great (313-337) the Christian faith became the religion of the empire and Byzantium its capital instead of Rome, and, further, when in 395 the Roman Empire was divided into the Eastern and the Western Empire. This Western Empire disappeared in 476, when Romulus Augustus, the last emperor, was deposed by Odoacer, the leader of the Germanic soldiers, who made himself ruler in Italy. The land of the extinct Western Roman Empire came into the hands of different peoples, chiefly of Germanic extraction. In Gallia the kingdom of the Franks springs up in 486 under Chlodovech the Merovingian. In Italy, the kingdom of the Ostrogoths under Theoderich the Great, who defeated Odoacer, rises in 493. In Spain the kingdom of the Visigoths appears in 507. The Vandals had, as early as in 429, erected a kingdom in Africa, with Carthage as its capital. The Saxons had already gained a footing in Britannia in 449.
All these peoples were barbarians in the strict sense of the term. Although they had adopted Christianity, it took hundreds of years to raise them to the standard of a more advanced civilisation. And, likewise, hundreds of years passed before different nations came to light out of the amalgamation of the various peoples that had conquered the old Roman Empire with the residuum of the population of that empire. It was in the eighth century that matters became more settled. Charlemagne built up his vast Frankish Empire, and was, in 800, crowned Roman Emperor by Pope Leo III. Again the whole world seemed to be one empire, headed by the Emperor as its temporal, and by the Pope as its spiritual, master, and for an International Law there was therefore no room and no need. But the Frankish Empire did not last long. According to the Treaty of Verdun, it was, in 843, divided into three parts, and with that division the process of development set in, which led gradually to the rise of the several States of Europe.