This, the first of the two refections on the ‘affair of the Indies’, was written for the academic session 1537–8, but was not delivered until January 1539. Juan de Heredia, the copyist of this portion of P, gave the relection no title. From his introduction, it is clear that Vitoria began the lecture as a further discussion of forcible baptism (see the lectio on ST II-II. 10. 8, Appendix B), with particular application to the Indians. In the event, however, he delivered only the first of the three parts promised in the diuisio, the one dealing with the Spanish titles to the conquest of America. The second instalment of the relection, On the Law of War, delivered a few months later, did not directly address the two remaining parts (though Vitoria's answer to the question of forcible baptism is deducible from 3.1 §10 in that work).

The copyist Heredia paired the two relections and described both, in the colophon to On the Law of War, as De Indiis (‘On the Indies’). A later hand added the more accurate heading De bello contra Indos (‘On the War against the Indians’) at the head of the first folio; this is the origin of the title by which the relection is now known (see footnote 2).

In addition to the usual notes of variant readings from LS, there are also some references in the critical apparatus to G, fols. 445 – 62 (reproduced in Vitoria 1933 – 5: II. 519–29).