Earl of Cambridge
As a result of her indiscretions, including an affair with King Richard II's half-brother, John Holland, 1st Duke of Exeter (d. 1400), whom Pugh terms 'violent and lawless', Isabella left behind a tarnished reputation, her loose morals being noted by the chronicler Thomas Walsingham. According to Pugh, the possibility that Holland was the father of Isabella's favourite son, Richard of Conisburgh, 3rd Earl of Cambridge, 'cannot be ignored'.