Austuriani first appear in the historical record in the years 363–365, when they devastated the Roman province of Tripolitania with "more violence than usual", according to Ammianus Marcellinus.
[3] An inscription at Lepcis made between 408 and 423 honours Flavius Ortygius, military commander of Tripolitania, for suppressing the "furor of the Austuriani", suggesting a particularly serious raid.
[3] In one letter, he praises the general Anysius for a victory he achieved over one thousand Ausuriani that year in a tight defile with a unit of just forty Unnigardae.
[3] In the sixth-century epic Iohannis, the poet Corippus mentions a camel-riding people called the Austur who lived near the Syrtes during the time of John Troglita's campaigns (546–547).
[12] Corippus describes their fighting tactics thus: The warlike Austur, wary of joining an uncertain battle in the open field, creates walls and ditches by tying camels together, and places his mixed flock in a tight protective crown, so that he can entangle the attacking enemies and crush them when they get lost.
Then, springing forward, the savage Ilaguas kills the troops that are trapped in these ramparts, and safely takes possession of the field … They use the ram as a machine in their unspeakable wars and set up their tents in good order, having arranged their standards.
[17] The sudden appearance of the Austuriani in the written sources corresponds with changes in settlement patterns detectable in the archaeology of Tripolitania, "where open farms had disappeared almost entirely by the fourth century".