Samuel Pufendorf was a pivotal figure in the early German Enlightenment. His version of voluntarist natural law theory had a major influence both on the European continent and elsewhere in the English-speaking world, particularly Scotland and America. Pufendorf's An Introduction to the History of the Principal Kingdoms and States of Europe (1682) became one of his most famous and widely reprinted works. It went through multiple editions during the eighteenth century, but its impact has largely been forgotten. Pufendorf's histories exhibited the core notions of his natural law theory by describing the development and current, reciprocal relations of individual states as collective social agents engaged in securing their own and, thus, their members' interests, including self-preservation. Hence, they essentially functioned as vehicles for philosophical demonstration or justification. Moreover, by emphasizing empirical details and legitimating (in principle) a de facto politics of interest, the histories appealed strongly to the emerging nation-states of early modern Europe, which sought ratification of their external and internal actions, policies, and pedagogies. Pufendorf based his accounts on each country's own historians and took care to describe its position from its own current and historical perspectives. It was an appealing approach to political history, judging from the long and diverse publishing record of the work. This book will be of interest to anyone concerned with the history of international law and the development of historiography during the seventeenth and eighteenth centuries. It makes available to contemporary scholars and students a carefully edited, helpfully annotated, and historically situated English version of one of Pufendorf's most popular and influential works. Samuel Pufendorf (1632-1694) was one of the most important figures in early-modern political thought. An exact contemporary of Locke and Spinoza, he transformed the natural law theories of Grotius and Hobbes, developed striking ideas of toleration and of the relationship between church and state, and wrote extensive political histories and analyses of the constitution of the German empire. Jodocus Crull (d. 1713/14) was a German émigré to England, a medical man, and a translator and writer. Michael J. Seidler is Professor of Philosophy at Western Kentucky University. Knud Haakonssen is Professor of Intellectual History at the University of Sussex, England.