There is no better illustration of the paramount importance of a strong and independent Belgium to the peace of Europe than the series of wars which followed each other in such rapid succession during the seventeenth century. It is true that, in nearly every instance, the new situation created in the Netherlands cannot be given as the direct cause of these various conflicts, resulting from territorial ambitions, dynastic susceptibilities and even, as in the case of the Thirty Years' War, from circumstances quite independent of those prevalent on the Meuse and the Scheldt. But, whatever the nominal cause of these wars may have been, they certainly acquired a more widespread character from the fact that the Spanish Netherlands lay as an easy prey at the mercy of the invader and constituted a kind of open arena where European armies could meet and carry on their contests on enemy ground. It is not a mere chance that the separation of the Southern and Northern provinces coincided with a remarkable recrudescence of the warlike spirit all over Europe. The contrast between the fifteenth century, when the Seventeen Provinces constituted a powerful State under the dukes of Burgundy, and the seventeenth, when the greater part of it was ruined and undefended, at the mercy of foreign invasion, is particularly enlightening. All through the Middle Ages first Flanders, later the Burgundian Netherlands, had exerted their sobering and regulating influence between France, on one side, and England or Germany on the other. The Belgian princes were directly interested in maintaining peace, and, in most cases, only went to war when their independence, and incidentally the peace of Europe, was threatened by the increasing ambition of one of their neighbours. The system of alliances concluded with this object could not possibly prevent conflicts, but it certainly limited their scope and preserved Europe from general conflagration, the combination of the Netherlands with one Power being usually enough to keep a third Power in order. The weakening of the Southern provinces under Spanish rule thus caused an irreparable gap in the most sensitive and dangerous spot on the political map of Europe. Triple and Quadruple Alliances were entered into and inaugurated the system of Grand Alliances which was henceforth to characterize almost every European conflict and increase on such a large scale the numbers of opposed forces and the devastations accompanying their warlike operations. [_DUTCH POLICY_]