 Gilbert de Clare , 8th Earl of Gloucester , 7th Earl of Hertford , 10th Lord of Clare , 5th Lord of Glamorgan ( c . 10 May 1291 – 24 June 1314 ) was an English nobleman and a military commander in the Scottish Wars . In contrast to most English earls at the time , his main focus lay in the pursuit of war rather than in domestic political strife . He was the son of Gilbert de Clare , 7th Earl of Gloucester , and Joan of Acre , daughter of Edward I. The older Gilbert died when his son was only four years old , and the younger Gilbert was invested with his earldoms at the young age of sixteen . Almost immediately , he became involved in the defence of the northern border , but later he was drawn into the struggles between Edward II and some of his barons . He was one of the Lords Ordainers who ordered the expulsion of the king 's favourite Piers Gaveston in 1311 . When Gaveston was killed on his return in 1312 , Gloucester helped negotiate a settlement between the perpetrators and the king . 
