The Working Papers of Hugo Grotius is the first full-length study of the handwritten documents initially used by the author of Mare Liberum (1609) and De Jure Belli ac Pacis (1625) in his day-to-day activities as a scholar, lawyer, and politician, but subsequently incorporated into his own or other archives. Martine van Ittersum reconstructs a process of transmission, dispersal, and loss that started during Grotius’ lifetime and ended with the papers’ auction in 1864. This is also a study of archival afterlives. Our understanding of Grotius’ life and work is shaped by the conscious decisions of previous generations to retain or discard documents, frequently for the sake of individual lives and careers, family honour and/or larger political and religious ends.