 Gilbert de Clare was the son of Gilbert de Clare , 7th Earl of Gloucester – known as Gilbert ' the Red ' – who in 1290 married Joan of Acre , daughter of Edward I. As a condition for the marriage , the earl had to surrender all his lands to the king , only to have them returned jointly to himself and his wife for the lifetime of either . This grant was made on the condition that the lands would pass to the couple 's joint heirs , but if they were childless to Joan 's heirs from any later marriages . The younger Gilbert was born the next year , around 10 May 1291 , securing the inheritance for the de Clare family , but his father died only four years later , on 7 December 1295 , while the boy was still a minor . Because of the joint enfeoffment , Joan kept the custody of the family lands , and did homage to the king on 20 January the next year . 
