DRAMATIS PERSONAE
KING RICHARD THE SECOND
QUEEN ISABEL, Duchess of York, wife to King Richard
JOHN OF GAUNT, Duke of Lancaster - uncle to the King
EDMUND LANGLEY, Duke of York - uncle to the King
HENRY BOLINGBROKE, Duke of Hereford, son of John of Gaunt, afterwards King Henry IV
Isabella of Valois was only eight years old when she became Richard’s second wife in 1396, and Shakespeare seems to have conflated her character in the play with Richard’s previous wife, Anne of Bohemia (1366-1394): she’s never mentioned by her first name in the dialogue, and is depicted as an adult. 
 The happiness of their marriage, and Richard’s devotion, seems to be based the legendarily loving marriage he enjoyed with Anne, which is mentioned in Holinshed’s  Chronicles. 
 
 Marriage of Isabella and Richard, by Jean Froissart (1396),  via.
Richard II Characters of the Play