his undaunted Behaviour in marrying one Woman [Elizabeth Woodville] while he was engaged to another [Bona of Savoy],
Elizabeth Woodville
She was the daughter of Richard Woodville (later the 1st Earl Rivers). Her first husband, Sir John Grey, was killed fighting on the Lancastrian side at the battle of St. Albans (1461) in the Wars of the Roses.
Edward IV married her in secret in 1464, partly because the powerful Richard Neville, earl of Warwick, had other marriage plans for him to Bona of Savoy and partly because of Elizabeth’s Lancastrian connections. (Edward is a Yorkist)
Bona later married the Duke of Milan (and actually has quite a few portraits).
Portraits of Bona:
http://www.asn-ibk.ac.at/bildung/faecher/geschichte/maike/monalisa/g_eng/711a.htm