Richard of Conisburgh, 3rd Earl of Cambridge English nobleman and conspirator of the Southampton Plot (1375–1415) Parents Isabella of Castile, Duchess of York Edmund of Langley, 1st Duke of York Children Henry of York Richard of York, 3rd Duke of York Isabel of Cambridge, Countess of Essex Siblings Edward of Norwich, 2nd Duke of York Constance of York Partners Maud Clifford Anne Mortimer, Countess of Cambridge