The Istvaeones, also called Istaevones, are mentioned as a Germanic tribal grouping in the writings of Tacitus and Pliny the Elder (~1st century AD), they categorized them as one of the nations of Germanic tribes descended from one of the sons of Mannus, the other two such peoples were the Ingvaeones and who?
Istvaeones:  The other two such peoples were the Ingvaeones and Irminones.
i don't know