On 15 May 1266 Henry "Almain" Cornwall (age 30) and John Warenne 6th Earl Surrey (age 35) fought for the King at Chesterfield [Map] during the Battle of Chesterfield. Henry Hastings (age 31), John Clinton, Roger Mandeville, John Eyvil, Baldwin Wake (age 28) all fought on the rebel side. The rebel Robert Ferrers 6th Earl of Derby (age 27) was captured.