LEGION 20; VALERIA VICTRIX were there in the creation of Hadrian's wall. They were considered a legendary legion who flew the banner of a boar as they marched. Whenever other Legions were sufferings, they saw the banners of the XX to be a sign of sure victory.
The roman mindset was that of a marriage between military might and a spiritual mindset. Despite your victories against Rome, they would not stop until their goals and visions for the future had been forged.