 The attack was repulsed, and Grandison was fatally wounded, together with his cousin Edward St John, a son of his uncle Sir John St John.. Grandison did not die immediately, surviving until 29 September, when he died of a fever presumably related to the injury (Hyde explicitly states that the wound caused his death).He was interred at Christ Church Cathedral in Oxford.He left a widow and daughter impoverished by the war, and soon after his death his widow married his first cousin Charles Villiers, 2nd Earl of Anglesey.