Throughout the nineteenth century, international relations in Europe were dominated by five great powers - Britain, France, Russia, Austria and Prussia. The creation of this system has been located traditionally in the long struggle with revolutionary and Napoleonic France. By contrast, this study demonstrates that its origins lie half a century earlier. During the third quarter of the eighteenth century, the European states-system was transformed by the military rise of Russia and Prussia in the Seven Years War of 1756–63. Eastern Europe became pre-eminent, and during the 1770s Poland was partitioned for the first time, while Russia and Austria also seized territory from the Ottoman empire. Europe’s centre of gravity moved sharply eastwards, and by the later 1770s Russia was emerging as the leading continental power. This study, based upon manuscript and printed sources from six countries, provides the first comprehensive study of these crucial events.