The Iverni (, Iouernoi) were a people of early first mentioned in Ptolemy's 2nd century Geography as living in the extreme south-west of the island. He also locates a "city" called Ivernis (, Iouernis) in their territory, and observes that this settlement has the same name as the island as a whole, Ivernia (, Iouernia). The name Iverni has been derived from Proto-Indo-European *PiHwerjoHn, "the fertile land". It was probably once the name given to all the peoples of Ireland, but by Ptolemy's time had a more restricted usage applicable to the inhabitants of the south-west. These Iverni can be identified linguistically with the Érainn (Éraind, Érnai, Érna), a people attested in Munster and elsewhere in the early Middle Ages.