Arthur, Prince of Wales

Born in September 1486, Arthur was the eldest son of Henry VII and Elizabeth of York - his arrival a living seal on the union of Lancaster and York after decades of civil war. The Tudors needed him to last. By age eleven he was formally betrothed to Catherine of Aragon, daughter of Spain's Catholic Monarchs, the marriage meant to lock down an alliance against France and Scotland. They wed in 1501. Six months later, at Ludlow Castle in Shropshire, Arthur died - possibly of sweating sickness - leaving Catherine a teenage widow who insisted the marriage had never been consummated. Henry VII quickly moved to preserve the Spanish alliance by betrothing her to Arthur's younger brother, the future Henry VIII. That second marriage held for over twenty years, until Henry needed it not to: the question of consummation, dormant for decades, was dragged up to justify an annulment, cast as biblical transgression, and used as the lever that split England from Rome.