Editor's prefatory note gives author: Señor Don Iñigo Abbad. Cf. p. 6

From the Notas del Editor prologue: The editor of this edition received the original work from a person who had received it from the author directly but did not recall his name. Thus, it was first published as anonymous. After finding out the identity of the author, the author was contacted and he revealed that there were inaccuracies in his account that should be corrected prior to publishing. After deciding with the author to add the corrections as errata to the originally printed books, the author died and they were unable to get his corrections in. Instead, Antonio Valladares de Sotomayor procured the services of three (unnamed) writers and published this edition at the Imprenta de Don Antonio Espinosa in 1788.