Another historical document: the Treaty of Utrecht (April, 1713) - signed by the countries in conflict during the "War of the Spanish Succession" (1701-1714). It was "the beginning of the end" of that conflict and [maybe] the birth of the British hegemony on the Western world.
But, in spite of that, we have to pay attention to one thing: the document was written in French. In fact, France and its culture were the most influential power in the scope of diplomatic etiquette in Europe in that period. As a result of it, the French will remain as the language of the international relations throughout a century and beyond.