Who is Bran de Montfort from The Reckoning and what is their importance?

Bran de Montfort is the son of Simon de Montfort. He is to bring soldiers to Simon's aid in Evesham, and arrives too late. He is haunted by the images of his slain brother and father. Bran questions his loyalties and suffers with guilt over his failure to arrive in time for that battle. His brother Guy seeks to take vengeance from their cousin Hal in Italy, and Bran blindly follows knowing that it is wrong but unable to let another brother down. Guy murders Hal and a priest in a church in front of the congregation, earning him King Edward's wrath. Guy and Bran are excommunicated by the church and hunted relentlessly by King Edward. Bran leaves Guy to visit the Pope, seeking to return to God's grace. Hugh de Whitton never leaves Bran's side, and watches him die of fever. Hugh's loyalty to Bran earns him a special place in the de Montfort household.