“The papacy pushed its universal claims and international organization to their highest point and defeated the rival universal claims of the Holy Roman Empire, only to be defeated, in its turn, by the regionally based monarchies.

“Here was the turning point of internationalism in the Middel Ages. The distinguished philosopher-historian Arnold Toynbee saw it as the point where the history of European society took a tragically wrong turn which would lead, almost inevitably, to the ultimate fall of this society. It seems rather that the turning away from internationalism occurred not because something went wrong in the development of European society, but, on the contrary, because this development was proceeding very successfully. The internationalism of the central Middle Ages which, as has been shown, was the internationalism of only a small educated and skilled class — this internationalism could have survived only if Europe had become an economicallu static and intellectual stagnant society. But this would have negated all the dynamic elements of this society deriving ultimately from the merging of the barbarian tribes with the advanced civilization of the late Roman Empire. It was the success of the international sector of medieval society in creating economic and cultural growth which fragmented Europe and undermined this sector itself. This fragmentation, in its turn, was a further dynamic element; for it increased variety and competition and thus forced men to modify traditions through reason and inventiveness. It was these characteristics which, by the end of the fifteenth century,were to give the Europeans their technological, military and political edge over native Americans, Africans and most Asians. They were conquered and sometimes enslaved. But the Europeans, too had to pay a price. They had to come to terms with the collapse of a unified Christendom and found themselves embarked on a course of apparently inescapable wars between states, all claiming the universality which seemed to have belonged to the Church. The achievements and the tragedies of European and human history cannot be easily separated.”

— H.G. Koeningsberger,
Medieval Europe 400-1500, page 279.