The two great conflicts which ushered in the eighteenth century added up to a real world war. Yet they developed without ever fundamentally influencing each other. Only on rare occasions, as in 1707, were the two European storm-centres in danger of merging. The belligerents of the Succession War stayed neutral in the war against Sweden, as did the Baltic belligerents in the war against France, although Denmark supplied the Maritime Powers with subsidy troops. Prussia joined in the western war even though the Great Northern War really concerned her much more.

The Grand Alliance of 7 September 1701 united the three powers which primarily waged the last and decisive war against the hegemony of Louis XIV: Austria, Britain and the United Provinces. In principle, Emperor Leopold I claimed the whole Spanish inheritance for the House of Habsburg. Without waiting till the treaty was signed, without even declaring war, he had sent an army into north Italy to try to occupy Milan, an Imperial fief which in his view reverted automatically to the Holy Roman Empire upon the death of Carlos II; the French troops acted in Lombardy only as auxiliaries of Philip V. The Maritime Powers, however, were not prepared in 1701 to fight for the strictly legitimist Habsburg claim. They undertook to assist the Habsburgs only to acquire ‘a just and reasonable satisfaction’ in Italy, the Spanish Mediterranean islands and the Spanish Netherlands, subject in this last case to the provision of ‘a dyke, rampart and barrier to separate and keep off France from the United Provinces’.