THE great European conflict which gives its name to the present volume of our History had a complicated origin, an unprecedented range, and far-reaching consequences. The story of its origin reaches back into a period dealt with in an earlier division of this work-- whether the Thirty Years' War be regarded, in the airy phrase uttered on a memorable occasion by Lord Beaconsfield, as "a war of succession for a duchy near Schleswig-Holstein," or as the inevitable result of deep- rooted religious differences not to be settled by ambiguous parchment compromises, or as the outburst of the storm brewed by militant Calvinism, or finally as the opportunity cautiously prepared and still more cautiously allowed to mature by the far-sighted statesmanship of France. After the War had broken out, not in the west but in an eastern border-land of the Empire, it gradually absorbed into itself all the local wars of Europe. The quarrels of the Alpine leagues and those about the Mantuan succession, the rivalries of the Scandinavian north and of the Polish north-east, the struggle, only temporarily suspended, of the United Provinces against Spain, the perennial strife between Spain and France for predominance in Italy and elsewhere--all contributed to the sweep of the current. Even the Ottoman Empire was concerned in its progress; for the "Turco-Calvinistic" combination announced by the pamphleteers was by no means a mere hallucination. "All the wars that are on foot in Europe," wrote Gustavus Adolphus to Axel Oxenstierna in 1628, "have been fused together, and have become a single war."
There was one exception which the Swedish King did not live to witness--the great English Civil War, which ran its course side by side with the last years of the Continental conflict, without at any point intersecting it. In the later years of the reign of her first Stewart King, England might have decisively influenced the great issues of