The evidence for these units in Britain comes from two separate sources, epigraphic evidence dateable to the early-2nd century recovered from two garrison forts in Northumberland and documentary evidence from the late-4th century Notitia Dignitatum which records one unit under the command of the Count of the Saxon Shore in southern England and another “at the disposal of the Right Honourable Duke of the Britains” in County Durham; the former two units separated by a distance of only 10 miles, the latter two by almost the entire length of the province. There is no evidence to link either of the 2nd-century units to either of the 4th-century units.
Numerus Exploratorum Habitanco The Company of Scouts from Habitancum
- Risingham (RIB 1235 AD 213; 1243; 1244).
Numerus Exploratorum Bremenio The Company of Scouts from Bremenium
- High Rochester (RIB 1262 altar AD 238-241; 1270 base).