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.
Son of another Robert de Ros (d. 1227) who rebelled against King John, was excommunicated by Innocent II, and was reconciled to Henry III. Robert the younger was Henry’s marshall of the household. He was sent to Scotland to assist Alexander III against his rebellious subjects, but was then deprived of his lands for cruelty to Alexander’s wife, Queen Margaret, who happened to be Henry’s daughter.
In consequence, he joined the Baronial party, and fought for de Monfort at Lewes. He was summoned to de Montfort’s parliament in 1264, and the Barony of de Ros (pronounced ‘Roose’) is considered by some to date from that event. The current holder of the title is thus considered England’s Premier Baron.