Lady Margaret Beaufort

Born 31 May 1443, a descendant of Edward III and second cousin to three kings, Margaret held a disputed thread to the English crown that seemed more burden than promise. She passed that claim to her son Henry Tudor, then spent the Wars of the Roses moving in shadows - working allies, timing the moment, positioning him to strike. Her manoeuvring came to a point at Bosworth Field in 1485, where Henry's forces cut down Richard III and ended the Plantagenet line. With her son crowned Henry VII, she held unusual political weight and autonomy at court, and turned her attention to legacy of a different kind: she founded Christ's College, Cambridge in 1505 and set the groundwork for St John's, completed after her death on 29 June 1509. A 19th-century Oxford hall bears her name - the first there to admit women.