The 6th Cohort of Nervians came from Belgium around the Brussels area and served on the Antonine Wall at Roughcastle.
They moved to Great Chesters Fort on Hadrian’s wall after serving on the Antonine Wall.
The altar above reads
VICTORIAE – to victory
COH VI NERVIORVM – the 6th cohort of Nervians
CC FL BETTO LEG XX VV – under the acting command of Flavius Betto, centurion of the 20th Legion Valiant and Victorious