In 1265, for his services during the Second Barons' War, he was given lands taken from Simon de Montfort's rebels.

In 1278, he decided to sell the manor and Leeds Castle to Queen Eleanor,[7] who cancelled all of his father's remaining debts.

[9] At some point thereafter, he was appointed commander of the king's own ships and ad hoc levies under a variety of titles that appear in various treaties and in items in the Gascon Rolls.

[12][13] The last is sometimes glossed as the later title "Admiral of the English Seas"[14] (Latin: Admirallus Maris Angliae).

[18] His second son Henry fought for the Earl of Lancaster at Battle of Boroughbridge, where he was taken prisoner and outlawed.