Margaret Beaufort, Countess of Devon

Lady Margaret Beaufort
Countess of Devon
Spouse(s)	Thomas de Courtenay, 13th Earl of Devon
Issue Thomas Courtenay, 14th Earl of Devon Henry Courtenay Sir John Courtenay Joan Courtenay Elizabeth Courtenay Anne Courtenay Eleanor Courtenay Maud Courtenay
Noble family	Beaufort
Father	John Beaufort, 1st Earl of Somerset
Mother	Margaret Holland
Born	c. 1409 Westminster
Died	1449 (aged c. 40)

Lady Margaret Beaufort (c.1409 – 1449) was a great-granddaughter of King Edward III (1327–1377).

Margaret Beaufort was the second and youngest daughter of John Beaufort, 1st Earl of Somerset (c.1371 – 16 March 1410), by his wife Margaret Holland (c.1385/6 – c.1439/40), the daughter of Thomas Holland, 2nd Earl of Kent by his wife Alice Arundel. Her father, John Beaufort, was an illegitimate son of John of Gaunt, 1st Duke of Lancaster (1340–1399), the third surviving son of King Edward III (1327–1377), by his mistress, later his third wife, Katherine Swynford. Margaret was thus a great-granddaughter of King Edward III.

Margaret had prominent siblings, including the following four brothers and a sister:

At some time after 1421 Margaret married Thomas Courtenay, 13th Earl of Devon (1414–1422), whom she bore three sons and five daughters. Her sons were all killed or executed during the Wars of the Roses due to their strong adherence to the Lancastrian cause, and left no children, and thus the senior line of the Courtenays was extinguished. Margaret's children included the following:

Two of Margaret's nieces were also named Margaret Beaufort. Margaret Beaufort, Countess of Stafford, was the mother of Henry Stafford, 2nd Duke of Buckingham, and Margaret Beaufort, Countess of Richmond and Derby, was the mother of King Henry VII.