They are mentioned as Sengalaunoì Σεγγαλαυνοὶ; var. σεταλλανοι by Ptolemy 2nd c. AD. A regio. Segovellaunorum is also attested by Pliny 1st c. AD.
The name Segovellauni chiefs-of-victory stems from Gaulish sego- victory attached to uellaunos chief, commandant.
The territory of the Segovellauni was located between the Rhone and the Drome rivers. They were in control of a section of the Isere river mouth, from which they held the Allobroges at bay. The Segovellauni nonetheless lived as clients of the neighbouring Cavares.
After the Roman conquest of the region, they were incorporated into the civitas Valentinorum or colonia Valentia, founded under Caesar or Augustus. A border land around Valentia Valence was probably detached from the territory of the Cavares and given to the smaller Segovellauni by the Romans, since Pliny 1st c. CE described the settlement as in agro Cavarum, whereas Ptolemy 2nd c. CE had it belonging to the Segovellauni.