Editing Lady Margaret Beaufort (section)

==Origins==
Lady Margaret Beaufort was the daughter and sole heiress of [[John Beaufort, Duke of Somerset]] (1404–1444), (a legitimised grandson of [[John of Gaunt]] and Gaunt's mistress [[Katherine Swynford]]), and John Beaufort's wife [[Margaret Beauchamp of Bletso|Margaret Beauchamp]]. Lady Margaret was born at [[Bletsoe Castle]], [[Bedfordshire]], either on 31 May 1441 or, more likely, on 31 May 1443. The day and month are not disputed, since she required [[Westminster Abbey]] to celebrate her birthday on 31 May.

The year of her birth is less certain. [[William Dugdale]], the 17th-century antiquary, suggested that she had been born in 1441, based on evidence of [[Inquisition post mortem|inquisitions ''post mortem'']] taken after the death of her father. Dugdale has been followed by a number of Lady Margaret's biographers; however, it is more likely that she was born in 1443, as in May 1443 her father had negotiated with the king concerning the wardship of his unborn child should he die on campaign.<ref>Jones & Underwood, 34.</ref>