[2] This unit would have had around a thousand men, including the specialist craftsmen needed to perform the skilled work of building the fort.

These men were probably Iberian Celts from the colony of Braga in Portugal, who seem to have been attached to the XX Legion Valeria Victrix in Chester.

[3] The First Cohort of Frisiavones were also present at Brocolitia, one of Hadrian's wall forts and settlements, at Carrawburgh, Northumberland.

Evidence for this relies on an inscription on an altar stone, which tells us that Optio Maus (an NCO within the Cohort) had repaid a vow to the goddess Coventina.

"Walls, 4 feet thick, composed of large boulder embedded in clay, with three courses of flagstones on the top, the outer face is of dressed stones 12 inches thick, 12 to 21 inches in length, the inner portion filled up with large boulders, clay and gravel; no inner wall has been discovered."

[8] As of 2020[update], it is on the Heritage at Risk Register, its condition described as "[g]enerally unsatisfactory with major localised problems".