The authors begin by tracing the service of Ednyfed Fychan and his descendants to the Welsh rulers of Gwynedd in the 13th century. They describe the familyś shift in loyalty to the Plantagenet rulers of England following Edward Iś conquest of Wales, and the eventual Tudor fall from power there as a result of joining Owen Glyndwrś rebellion against the Lancastrian Henry IV. Of the next generation only Owen Tudor achieved prominence, marrying Katherine Valois, a French princess and widow of the English king Henry V. Most of the book concerns Owen and Katherineś sons, Edmund and Jasper (who became respectively earls of Richmond and Pembroke under their half-brother Henry VI), and Edmundś son Henry. With his uncle Jasper, Henry endured a long exile in Brittany under the Yorkist ascendancy, before returning to defeat Richard III and take the crown at Bosworth Field in 1485. The authors provide valuable new insight into English politics during the Wars of the Roses, the use of Henry Tudor as a diplomatic pawn by France and Brittany, and the early career of the least-known Tudor monarch.