AWA409 - What did the Constitutio Antoniniana mean for the Roman auxilia?

Carlos, an economics professor (!), asks: Hi Murray,   I am a long-time AWM subscriber, born in Hispania, working in Britannia, and mostly living in Raetia. Love the podcast.   My question is this. With the Constitutio Antoniniana, all young men within the Imperium became citizens and could enlist in the legions instead of the auxilia. Hence, the auxilia presumably attracted less recruits. With Diocletian's reforms, whatever remained of the auxilia was absorbed into a fully new structure with limitanei, comitatenses, and auxilia palatina, the latter being elite. This suggests that the distinction between legions and auxilia might had become fuzzy at that point, else one could just have assigned the auxilia to the borders.   What do we know about the evolution of the auxilia from the Constitutio Antoniniana to Diocletian's reforms? Were they still around, with named units slowly vanishing for lack of recruits, or did they become something else by enlisting non-citizens? Did they become part of a wild mixture of units with all-barbarian numeri in the chaos of the third century and its many revolts? Surely, at the very least, Tacitus' old statement that auxiliaries and legionaries were roughly equal in number is no longer valid for the third century? Murray Investigates.   Join us on Patreon patreon.com/ancientwarfarepodcast