The history of Commentary on the Law of Prize and Booty is complex. When Grotius’s personal papers were auctioned in The Hague in 1864, Dutch scholars discovered that his famous Mare Liberum was just one chapter in a manuscript of 163 folios, written in justification of Jacob van Heemskerck’s capture of the Santa Catarina, a Portuguese merchantman, in the Straits of Singapore in February 1603. A prominent Dutch historian of the nineteenth century, Robert Fruin, persuaded the classical scholar H. G. Hamaker to transcribe and publish it, and the Latin text was issued in 1868. This Liberty Fund edition is based on the one prepared by Gwladys L. Williams and Walter H. Zeydel for the Carnegie Endowment for International Peace. It combines a revised text and new material, making it a highly attractive edition of a work that is difficult to obtain.