While he knew the Riverlands almost better than everyone else, he was declared an outlaw and couldn't stay there. The Vale was not an option, as his face was also well-known. So he snuck into the vast North, where nobody would look for him. He grew a short beard and dyed it, and his hair black. After discarding all the heraldry that would give him away, Brynden took the role of a poor old hedge knight, taking small jobs clearing out ironborn or bandits.