Mentioned only on military diplomata dated from the late-first to the mid-second centuries AD, the garrison post(s) of this unit remains unknown. The title Proculeiana presumably commemorates a former commander of the unit named Proculeianus.
Evidence for the presence of Ala Augusta Gallorum Proculeiana civium Romanorum in Britain
- Cil Xiii.3606 Ager Nerviorum – Diploma; dated: c. AD98,
- L’Année Épigraphique 1997.1779a diploma dated c. AD126,
- L’Année Épigraphique 1997.1001 diploma dated 27th February AD158,