The Lady of the Rivers: A Novel (The Plantagenet and Tudor Novels) by Philippa Gregory

Jacquetta, daughter of the Count of Luxembourg and kinswoman to half the royalty of Europe, was married to the great Englishman John, Duke of Bedford, uncle to Henry VI. Widowed at the age of 19, she took the extraordinary risk of marrying a gentleman of her household for love, and then carved out a new life for herself.