During the third quarter of the eighteenth century, the European states-system was transformed by the military rise of Prussia and Russia. Eastern Europe became pre-eminent and during the 1770s, Poland was partitioned for the first time by its three neighbors, and two—Russia and Austria—also seized territory from the Ottoman empire. Europe's political center of gravity moved sharply eastwards, and by the later 1770s Russia was emerging as the leading continental state. Based on sources in six countries, this study provides the first survey of these crucial events.