Medieval Theory of International Relations. In the Middle Ages local dominion took the place of world dominion, and the principles of universal law were pushed into the background. The medieval period has been called an age of organized anarchy. The wager of battle was a recognized form of judicial trial, private warfare was common, and trade was hindered by pirates at sea, by robbers on land, and by numerous feudal tolls and exactions.
While the church tried to maintain peace and to ameliorate the conditions of warfare, and while the ideals of chivalry tended somewhat to humanize the conduct of the nobles, it was not until the power of the kings had established royal justice over their dominions that life and property were safe and order was established. The spirit of provincialism was deeply ingrained.
At the same time, the theory of world dominion survived as an ideal, and The Holy Roman Empire made pretensions to world supremacy as pompous as they were impossible. The spirit of localism, gradually developing into sovereign national monarchies, prepared the way for international relations; the survival of the imperial concept impeded this process.
The church, more powerful than the state during the greater part of the medieval period, treated each rising nation as a separate unit and recognized the national spirit. At the same time, in its world organization, in its emphasis on a common Christian brotherhood, and in its uniform doctrine for all Europe, it expounded the principles of internationalism.
The Roman Empire had extended its sway over so large a part of the world of its day that it recognized the existence of no other legal state, and could not, therefore, work out a system of international law. The church was not able to maintain its claim to world dominion, nor to prevent the rise of independent states, too nearly equal for any one to exercise supreme authority. Within this society an international law could develop.
Besides, the efforts of the church to curb private warfare and to apply the principle of arbitration in settling disputes furthered the idea of international regulation. Kings, eminent jurists, and cities also acted as arbitrators during the Middle Ages; and feudal principles predisposed vassals to accept their overlords as judges. During the thirteenth century there were said to have been one hundred cases of arbitration in Italy alone.
During the fourteenth and fifteenth centuries arbitration declined and by the seventeenth century had practicality disappeared. The use of the Latin language as the common tongue of education and of the church was a bond of unity; and the papal legates sent from Rome on various duties and the permanent ambassadors maintained by the papacy at certain courts contributed to the practice of diplomacy.
As early as the seventh century, a Spanish churchman, St. Isadore of Seville, made a clear distinction between the Roman jus naturale and jus gentium, and applied the latter to what we now consider international law. This distinction was incorporated later into Gratian
s code of canon law and became an accepted truism of ecclesiastical jurisprudence.
The revived study of Roman law by the jurists of the twelfth century furnished a necessary foundation for the growth of royal power that created independent sovereign states, and for the development of the principles of international jurisprudence.
The idea of territorial sovereignty, inherent in the feudal system, also bore fruit, after the idea of universal empire disappeared, and the study of Roman law made it natural to look upon the kings as the owners of their territories with full sovereignty over them.
The crusades of the twelfth and thirteenth centuries exerted an important influence on international relations. They brought peoples of various countries together in a common undertaking, stimulated the exchange of ideas, and strengthened the concept of the unity of Christendom.
By weakening the resources of the nobles, they helped to destroy feudalism, thus aiding the kings and the free cities. They also gave a decided stimulus to trade and to the formation of codes of maritime law which influenced later international jurisprudence.
As early as the twelfth century, consuls represented the interests of the merchants of the Italian cities in Mohammedan countries; and as early as the thirteenth century, Venice established a diplomatic service and laid down rules for the guidance of its ambassadors. At the close of the Middle Ages, the kings of the rising national states, eager to consolidate and to expand their kingdoms, adopted many of the diplomatic methods and ideals of the Italian cities.
The conditions of the early medieval world made international law, in the modern sense of the term, impossible. The rival claims of church and state, the complicated but unorganized political system of feudalism, the ideal of world unity, and the local independence of principalities and cities prevented the conception of sovereign states, independent and legally equal, with a balance of power maintained among them.
The influence of the church prevented international relations, not only by emphasizing the unity of Christendom, but also by discouraging legal relations with the Mohammedan world. The just treaty which the forward-looking emperor, Frederick II, negotiated with the Sultan of Egypt was an unforgivable offense from the papal point of view.
But medieval ideas were dispelled by the Renaissance and the Reformation. Local disorganization was overcome by the rise of national monarchies, and in the fifteenth century the idea of the balance of power was applied in the relations of the leading Italian cities.
The concepts of international law were worked out by the group of jurists that culminated in Grotius; international wars, political and religious, led, in time, to the calling of the first great international conferences and to the framing of the international treaties of Westphalia.