The history of Commentary on the Law of Prize and Booty is complex. When Grotiuss personal papers were auctioned in The Hague in 1864, scholars discovered that Mare Liberum was just one chapter in a manuscript of 163 folios, written in justification of the capture of the Portuguese merchantman Santa Catarina in the Strait of Singapore in February 1603. Robert Fruin persuaded the scholar H. G. Hamaker to transcribe and publish it in 1868.Knud Haakonssen, the General Editor of the Natural Law and Enlightenment Classics series, states, Grotiuss work on the right of prize and booty is unusual. It has been argued in some of the most prominent recent scholarship that the work, while never published by Grotius himself, was the intellectual resource for much of his most important work. One chapter of the manuscript was used for his famous work on the free sea, Mare Liberum, and many of the most important features of his greatest work, De Jure Belli ac Pacis (The Rights of War and Peace), are either derived from, or revised versions of, the earlier writing.The 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 the original text and new material.Martine Julia van Ittersum is a Lecturer in History at the University ofDundee.Knud Haakonssen is Professor of Intellectual History and Director of the Centre for Intellectual History at the University of Sussex, England.