This is the first critical edition of the earliest known Latin commentary on Aristotle's Prior Analytics, the Anonymus Aurelianensis III. In addition to the critical text, Christina Thomsen Thornqvist's edition contains a comparative analysis of the anonymous commentary and the extant Greek commentaries as well as a full comparison between Boethius' translation and the translation used by the commentator. The edition provides a solid foundation for further study on the earliest medieval exegesis on the Prior Analytics and is an essential resource for any scholar who wants to learn more about the development of logic in general and the medieval reception of Aristotelian syllogistic in particular.