[1] He was a supporter of Simon de Montfort which earned him a suspension from office on 1 December 1265 by the papal legate Ottobuono, but after traveling to Rome, he was absolved by Pope Gregory X on 26 November 1272.
King Edward I of England however, confiscated his lands on his return from Rome, only restoring them to the bishop on 20 April 1273.
[1] Stephen served as one of the three electors of the nine members of the council that Montfort set up after the Battle of Lewes in 1264.
Bersted served with Montfort himself and Gilbert de Clare, Earl of Gloucester.
[5] By June 1276 he was back in royal favor, for King Edward I of England attended the ceremony held that month where Bersted oversaw the translation of the relics of Richard of Chichester to a new shrine.