WHEN in the last months of 1648 was signed the great peace which brought to an end the Thirty Years' War and with it the mediaeval polity which it finally destroyed; as the army of diplomats whose work it was dispersed to their respective governments, the awe-inspiring mass of documents which formed the fruit of their long labors might have led men to believe that Europe would hasten to enjoy the peace which she so needed and which her people for the most part so greatly desired. But whatever hopes of quiet were entertained, were already far on the way to disappointment; for the Europe to which the diplomats returned was even then altered or altering before their eyes and already shaping itself for new conflict. Scarcely a state of any consequence prepared to recruit its resources by the arts of peace; scarcely a royal house but faced a crisis in its fortunes; scarcely a people but was stirring in unrest or already engaged in revolution. So far from ushering in a period of peaceful progress the Westphalian treaties became the starting point for new and bloody rivalries.