T. F. Tout, The history of England, from the accession of Henry III. to the death of Edward III.…
“ As the inaction of Lancaster kept the northern barons quiet, Edward's sole task was to wreak his revenge on the marcher lords. They were unprepared for resistance, and waited in vain for Lancaster to come to their help. Without a leader, they made feeble and ill-devised efforts to oppose the king's advance. Their command of the few bridges over the Severn prevented the king from crossing the river, and leading his troops directly into the march. Foiled at Gloucester, Worcester, and Bridgnorth, Edward made his way up the stream to Shrewsbury. ”
