Writing about international relations and diplomacy during the ‘long eighteenth century’ has been dominated by the language and approach of great power rivalry. Ever since Leopold von Ranke's seminal essay of 1833 on ‘The Great Powers’, these decades have been studied in terms of the contested rise of new states. The emergence of the Pentarchy (France, Austria, Britain, Prussia and Russia) and the rivalries which accompanied it, have dominated eighteenth-century international history. Significantly, this period saw the appearance of the very term ‘great powers’ as a way of defining and identifying the states which dominated Europe both individually and collectively. It witnessed a second, related change in the political lexicon, as the word ‘diplomacy’ came to assume its modern meaning. When in the later seventeenth century the Maurist monk Jean Mabillon wrote his great study of historical method and the science of documents, De re diplomatica (1681), the word ‘diplomatic’ retained its traditional meaning: pertaining to the study of documents or diplomas. The peaceful conduct of international relations was at this period known as ‘négociations’. By the closing years of the eighteenth century the word ‘diplomacy’ had assumed its more familiar sense, that of the peaceful and continuous management of relations between states. The precise point at which the change occurred remains elusive: but by the 1790s and perhaps even the 1780s, it had taken place.