Keen local historian Jon Gunson has compiled this series entitled Friday Knight - knights who fought at the Battle of Lewes - giving each a brief biography.
Any damn’ fool can start a war; it takes a wise man to stop one. By 1266, there were those at King Henry’s court who understood that a wounded polity cannot be healed without compromise. Perhaps this is why Sir Richard got away with claiming that he had been with Simon de Montfort in 1264-5 “by constraint” - i.e., a big boy made me do it. I bet six months under siege at Kenilworth was not much fun if your heart wasn’t in it. Though the feudal system assumes loyalty, and perhaps it is unfair to underestimate the problems this must have caused.