The Reckoning — Sharon Kay Penman

England, 1271: The last year of the reign of Henry III. Five years have passed since the brutal slaying of Simon de Montfort assured the puppet king his throne. In truth, though Henry wears the crown, his son Edward rules the kingdom.

For de Montfort's family, these years have meant anguish and exile. For his Welsh ally Llewelyn ap Gruffydd, ruling uneasily over his fractious countrymen, they have meant a tense, unstable truce with Edward, now casting covetous eyes on Wales. Once plighted to Simon's daughter Ellen, but released from that troth by her father's death, Llewelyn has never married. He has named his charming but untrustworthy brother Davydd as heir, knowing full well the danger.

The Reckoning is a novel about a Celtic society on a collision course with a formidable feudal realm ruled by the most predatory of Plantagenet kings. But it is also a story of broken fortunes and grim vengeance, of the poisoned love between two brothers and the rare love between a man and a woman who overcame nearly insuperable obstacles to form a bond that would never break Above all, it is about two extraordinary men whose dreams were so large and so antithetical that they were destined to clash in a conflict that brooked no compromise.