In De jure belli ac pacis, Grotius constructs international law with the vocabulary of private law. For this purpose, he uses distinctions from the Institutes of Justinian and the Digest, but redefines key concepts of Roman law, such as natural law or law of nations (jus gentium). In doing so, he uses a method that is typical for humanist jurisprudence. On the one hand, he describes history, on the other hand, he renews the traditional system of law and adapts the law to the needs of his own day and age.

What is the legacy of Grotius’ doctrinal efforts, and how did they impact on current structures of international law? Was he providing a natural law foundation for the global order, or rather an instrument of power for sovereigns to assert their political and commercial dominion over the world?

Written in captivity in 1619-1621 and first published in 1631, Grotius’ Inleidinge tot de Hollandsche Rechts-geleertheyd was the first-ever comprehensive introductory textbook on Hollandic (private) law and jurisprudence in the Dutch language. It became one of the key and even founding texts in the tradition of Roman-Dutch law. This contribution first focuses on the writing and publication process, as well as on the aim, style and structure of the work. Afterwards, the main ideas of the Inleidinge on the law of persons, property law and the law of obligations are summarized. Finally, the fate and influence of the Inleidinge after Grotius’ death are briefly highlighted.