The Spanish foreign policy during the reign of Charles II, the last king of Spanish Habsburgs, it is little-known, in especial the relation ships with the Emperor. During the second half of the 17th century the political and military relation ships with the Holy Roman Empire changed notably with regard to those developed during theThirty years war, when the Spanish political and military interventionism arrived to itspeak in the European continent. During Charles’s II reign the weakness of the monarchandthe successorial problems marked the relationships of many of the European nations.Throughout this time the military and financial collaboration between both branches of the Habsburgs was more necessary than never, although the things had changed notably.Spain, although his need of money, it gave generous subsidies to the Emperor trying toensure their military collaboration with German recruits for the Spanish armies and military help to defend their European possessions from the French expansionism. But theresult of this collaboration was not the expected one, which contributed to the separation between both monarchies and to that the Succession of the monarchy didn’t relapsein imperial candidate. Along this article this military collaboration is analyzed, pointingat new keys for the analysis of the relations between the Hispanic Monarchy and theEmpire.