Margaret Beaufort, Countess of Richmond and Derby (d. 1509)
Lady Margaret Beaufort (usually pronounced: BOH-fərt or BEW-fərt; 31 May 1441/43 – 29 June 1509) was a major figure in the Wars of the Roses of the late fifteenth century, and mother of King Henry VII of England, the first Tudor monarch.

A descendant of King Edward III, Lady Margaret passed a disputed claim to the English throne to her son, Henry Tudor. Capitalising on the political upheaval of the period, she actively manoeuvred to secure the crown for her son. Beaufort's efforts ultimately culminated in Henry's decisive victory over King Richard III at the Battle of Bosworth Field. She was thus instrumental in orchestrating the rise to power of the Tudor dynasty. With her son crowned Henry VII, Lady Margaret wielded a considerable degree of political influence and personal autonomy – both unusual for a woman of her time. She was also a major patron and cultural benefactor during her son's reign, initiating an era of extensive Tudor patronage.

She is credited with the establishment of two prominent Cambridge colleges, founding Christ's College in 1505 and beginning the development of St John's College, which was completed posthumously by her executors in 1511. Lady Margaret Hall, Oxford, the first Oxford college to admit women, is named after her.