[7] At the battle of Lincoln in 1217 Peter led a division of the royal army and earned some distinction by his valour; but he played a secondary part in the government so long as William Marshal held the regency.

After Marshal's death in 1219 Peter led the baronial opposition to Hubert de Burgh, with varying success.

[10] In 1225 a plot to ship Eleanor of Brittany, who as cousin to Henry III always posed a potential threat to the crown and was thus viewed as a state prisoner and then confined at Bristol Castle, away to France, was reported.

The plot might have been false and only fabricated to discredit Peter, and he eventually fell out of royal favor in spring 1234.

[7] On July 30th 1232 Hubert de Burgh was overthrown by the action of Peter des Roches who then became the chief minister of Henry III.

[4] The Lanercost Chronicle relates that Peter, out hunting one day, encountered King Arthur, dined with him, and asked for a token of their meeting.