 The decision to conquer the area was taken by the Romans after the revolt of Venutius threatened to make the Brigantes and their allies, such as the Carvetii, into anti-Roman tribes, rather than pro-Roman ones which had previously been the case.After a period of conquest and consolidation, based on the Stanegate line, with some coastal defences added, Hadrian decided to make the previous turf wall into a solid one.Although abandoned briefly in favour of the more northerly Antonine Wall, the Hadrianic line was fallen back upon and remained for the rest of the Roman period.