In 1746, Gainsborough married Margaret Burr, an illegitimate daughter of the Duke of Beaufort, who settled a £ 200 annuity on the couple.

The descendants of an illegitimate child of English Royalty would normally have no claim on the throne, but the situation was complicated when Gaunt and Swynford eventually married in 1396, when John Beaufort was 25.

John Beaufort's granddaughter Lady Margaret Beaufort, a considerable heiress, was married to Edmund Tudor, 1st Earl of Richmond.

Edmund married Margaret Beaufort, a lady of royal descent, whose son became King Henry VII.

The Beaufort children, three sons and a daughter, were legitimised by royal and papal decrees after John and Katherine married in 1396 ; a later proviso that they were specifically barred from inheriting the throne, the phrase (), was inserted with dubious authority by their half-brother Henry IV.

James's relationship with the House of Lancaster changed in February 1423 when he married Joan Beaufort, a cousin of Henry VI and the niece of Thomas, Duke of Exeter and Henry, Bishop of Winchester.

He married the daughter of Sir Thomas Neville of Horneby, Margaret Neville, who bore him one son, Henry Beaufort.

Margaret married John Beaufort, 1st Earl of Somerset, son of John of Gaunt, 1st Duke of Lancaster and his mistress Katherine Swynford.

* Lady Joan Beaufort ( c. 1406 – 15 July 1445 ), who married James I of Scotland and Sir James Stewart, the Black Knight of Lorn.

* Lady Margaret Beaufort, Countess of Devon ( c. 1409 – 1449 ), married Thomas de Courtenay, 13th Earl of Devon.

After Beaufort died in 1410 ( in the Tower of London ), she married his nephew Thomas of Lancaster, 1st Duke of Clarence, the son of King Henry IV.

This did him no harm, however, even after Warwick was toppled from power, and in 1482, with the House of York now occupying the English throne, he married his second wife Lady Margaret Beaufort, whose son, Henry Tudor, was the leading Lancastrian claimant.

He married Lady Margaret Beaufort, and fathered Henry Tudor, the future king.

His eldest son Thomas Stanley, 2nd Baron Stanley, married Lady Margaret Beaufort, the mother of King Henry VII, and also Eleanor Nevill.

The earliest known possible Fry ancestor is supposed to be Richard Fry who married secondly Joan Beaufort, great granddaughter of John of Gaunt.

In 1452 Lady Margaret Beaufort, the nine-year-old daughter of the Duke of Somerset was summoned to the court of her second cousin, King Henry and, at Bletsoe Castle on 1 November 1455, married to Edmund.

Following the death of his first wife he married to Lady Mary Somerset, Lady of the Bedchamber and daughter of the Duke of Beaufort and Mary Capel in 1685 ; they had a son and two daughters.

César, duke of Vendôme, took part in the disturbances which went on in France under the government of Cardinal Richelieu and of Cardinal Mazarin ; he was the father of Louis, Duke of Vendôme, who married a niece of Mazarin, and François de Vendôme, Duke of Beaufort.

Humphrey Stafford married Lady Anne Neville, daughter of Ralph de Neville, 1st Earl of Westmorland and Lady Joan de Beaufort, before 18 October 1424, They had the following children:

Margaret Beaufort had previously been married to Edmund Tudor, the eldest half-brother of Henry VI, and had given birth to the future Henry VII two months after Edmund's death.

The children of Earl Ralph's first wife had made good marriages to local nobility, but his Beaufort children married into even greater families.

* Princess Mary of Teck, later The Lady Mary Cambridge ( 12 June 1897 – 23 June 1987 ); married 1923 the 10th Duke of Beaufort ( 4 April 1900 – 4 February 1984 ).

* Sir Ralph Neville ( c. 1392-25 Feb 1458 ), married Mary Ferrers, his stepsister, daughter of Sir Robert Ferrers and Joan Beaufort ( 1379 – 1440 ) and had issue.

* Margaret Holland ( 1385 – 31 December 1439 ), married first John Beaufort, 1st Earl of Somerset and second Thomas of Lancaster, 1st Duke of Clarence

* Ferdinande de Lesseps ( Paris, 3 December 1872-Paris, 4 May 1948 ), married firstly in Paris on 10 May 1890 to Ferdinand de Gontaut-Biron ( Paris, 11 November 1868-Château de Kimpempois, 6 December 1898 ), of the Marquesses of Saint-Blacard, by whom she had a son Ferdinand de Gontaut-Biron ( Paris, 25 January 1892-Paris, 2 February 1892 ), and married secondly François-Joseph de Cassagne de Beaufort, Marquis de Miramon ( 1867 – 1932 )

* 1511 – St John's College, Cambridge, England, founded by Lady Margaret Beaufort, receives its charter.

Despite his apparent affiliation with Richard, Baron Stanley's wife, Lady Margaret Beaufort, was Henry Tudor's mother.

It was renamed Christ's College and received its present charter in 1505 when it was endowed and expanded by Lady Margaret Beaufort, mother of King Henry VII.

* April 9 – St John's College, Cambridge, England, founded by Lady Margaret Beaufort, receives its charter.

* June 29 – Lady Margaret Beaufort, mother of Henry VII of England ( b. 1443 )

* February 7 – John de la Pole, 2nd Duke of Suffolk, marries Lady Margaret Beaufort.

* May 31 – Lady Margaret Beaufort, mother of Henry VII of England ( d. 1509 )

Lady Alice's family, the Neville's, were already established at court being descendants of John of Gaunt's daughter Lady Joan Beaufort and her second husband, Ralph Neville, 1st Earl of Westmoreland.

Elizabeth and Buckingham now allied themselves with Lady Margaret Beaufort and espoused the cause of Margaret's son Henry Tudor, a great-great-great-grandson of King Edward III the closest male heir of the Lancastrian claim to the throne with any degree of validity.

Elizabeth's mother, Elizabeth Woodville, made an alliance with Lady Margaret Beaufort, mother of Henry Tudor, who was the closest to Royalty the Lancastrian party possessed.

As queen, Elizabeth did not exercise much political influence, due to her strong-minded mother-in-law Lady Margaret Beaufort, but she was reported to be gentle and kind, and generous to her relations, servants and benefactors.

The college was founded by Lady Margaret Beaufort.

The gatehouse is crenelated and adorned with the arms of the foundress Lady Margaret Beaufort.

The College motto is souvent me souvient, supplied by Lady Margaret Beaufort, and written in Mediaeval French.

Only the female line of Somerset's uncle, the 1st Duke of Somerset, remained, represented by Lady Margaret Beaufort and her son Henry Tudor.

Henry VII, who became King of England in 1485, derived his claim to the throne from his mother Lady Margaret Beaufort, who was a great-granddaughter of Gaunt and Katherine Swynford.

Lady Margaret Beaufort

Lady Margaret Beaufort at prayer, later copy by Rowland Lockey, perhaps of a contemporary original

* 1443-1455: Lady Margaret Beaufort

* Betty King, The Lady Margaret, pub 1965, a story about the marriage of Margaret Beaufort and Edmund Tudor, parents of King Henry VII

Through her father, Lady Margaret Beaufort was a granddaughter of John Beaufort, 1st Earl of Somerset, a great-granddaughter of John of Gaunt, 1st Duke of Lancaster and his mistress and third wife Katherine Swynford, and a great-great-granddaughter of King Edward III of England.

* Jones, Michael K .; Underwood, Malcolm G. The King's Mother: Lady Margaret Beaufort, Countess of Richmond and Derby, Cambridge University Press 1993 ISBN 0-521-44794-1