nobility, the great monarchies of Europe began to acquire strength and consistency, and to assume something of their present territorial form. These governments were absolute in character, and although some of them were at times administered with considerable liberality, in none were popular rights recognized, and none were limited by representative institutions. Not only were they absolute in form, but in most of them the idea of sovereignty had become associated with the person and dignity of the ruler. He was the head of the state; the title to its territory and property was vested in him, and he was held to be able to dispose of it at will. Such restraints as were established upon his power had chiefly to do with internal affairs, and rarely extended to his foreign relations. He declared war, engaged in alliances, offensive and defensive, entered into treaty stipulations, increased or diminished his territories by sale, gift, or exchange, for such reasons as commended themselves to his judgment, or to his views of propriety or expediency; as a result diplomatic relations soon became common, alliances were entered into, agents were established at foreign capitals, through whom information was obtained as to the policies and intentions of foreign powers. Embassies were sent and received, ambassadors maintained, and great wars were undertaken. Conquests were made, and territory changed hands; sometimes as a result of war, sometimes by treaty after the manner of a transfer of property among private individuals.
Such intricate and important international relations could not long exist without furnishing precedents of sufficient value to be cited in negotiation, or without some practices and usages acquiring, by frequent repetition or general consent, the binding force of international customs. The sea laws furnished a basis upon which to erect a code of maritime laws; their experience in war and negotiation furnished the states of Europe with an abundance of material for the preparation of a code of international usages, and the Roman law furnished a stock of legal maxims and principles with which to bind the whole fabric together.
While the statesmen of Europe, so late as the first half of the seventeenth, century, still lingered in the shadow of an imperial idea which the Protestant reformation had made impossible of realization, they were assisted in finding a way out of the difficulties which encompassed them by the occurrence of a great war and the advent of a great writer. The Thirty Years' War, then in full progress, had been marked by a refinement of barbarous cruelty, and by acts of atrocity perpetrated upon the unarmed and unoffending inhabitants of the valley of the Rhine, which stand without a parallel in the history of war. Many of the military operations had been undertaken rather with a view to pillage than from a desire to injure or defeat the enemy. Population had diminished, great areas of territory had been laid waste, and commerce and manufactures had well-nigh disappeared. With an experience of the horrors of war so bitter and long continued as that which Europe was then undergoing, it is not remarkable that men should have been willing to listen to any scheme which promised to mitigate the severity of war or to lighten, in any degree, its terrible burdens.
But great as had been the losses in men and material wealth, it may be doubted whether a desire to ameliorate the existing usages of war would have been of itself an agency sufficiently potent to bring about a reform of international law had not another and more powerful factor contributed directly to the same end. In the course of the war the old idea of papal and imperial supremacy had finally disappeared. The ancient standard of international obligation had ceased to exist, and a newer and more enduring standard had to be erected in its place. As the idea of a common earthly superior was no longer recognized, it became necessary to invent a theory which, while conforming to existing political conditions, should furnish a safe and practicable rule for the conduct of interstate relations.
The great writer was Hugo Grotius, a native of Delft, in Holland, the founder of the modern science of international law. The materials for his work were drawn from two principal sources, the law of nature—the jus gentium of the Romans—and the tacit or express consent