Margaret Beaufort, Countess of Richmond and Derby
Lady Margaret Beaufort , Countess of Richmond and Derby , was the mother of King Henry VII and paternal grandmother of King Henry VIII of England.
Margaret was born at Bletsoe Castle, Bedfordshire, onMay 1443 or 1441. The day and month are not disputed, as she required Westminster Abbey to celebrate her birthday onMay. The year of her birth is more uncertain. William Dugdale, the 17th century antiquary, has suggested that she may have been born in 1441 this suggestion is based on evidence of inquisitions taken at the death of Margarets father. Dugdale has been followed by a number of Margarets biographers however, it is more likely that she was born in 1443, as in May 1443, her father had negotiated with the king about the wardship of his unborn child in case he died on a campaign.
Source: Wikipedia