Joan DE BEAUFORT, Countess Of Westmorland 
- Born: 1379, Le Château, Beaufort, Pays-De- Loire, France
- Marriage: Sir Ralph DE NEVILLE, Knt, 1St Earl Of Westmorland 
- Died: 12 Nov 1440, Howden, Yorkshire, England at age 61
- Buried: Lincoln Cathedral, Lincolnshire, England
Another name for Joan was Jeanne.
Sources, Comments and Notes:
[1338 Joan DE BEAUFORT, Countess of Westmorland. Birth Date before Marriage Date of Parents. (pm. 13 Jan 1396 and b. Abt 1375) This person was born before the marriage of his/her parents. Verify the birth and marriage dates.
Explanation <Wikipedia>: "La maison de Beaufort est une branche légitimée de la maison de Lancastre, issue des enfants du mariage de Jean de Gand, duc de Lancastre et de Catherine Swinford, née de Roet, et sœur de la femme de Geoffrey Chaucer.
Ces enfants sont en effet nés avant que Jean de Gand et Catherine Swinford ne soient mariés, et le premier dans le château de Beaufort en Champagne (aujourd'hui Montmorency-Beaufort), donnant ainsi le nom à la maison qui descend de lui.]
"Lady Joan Beaufort, Countess of Westmorland
Spouse Ralph de Neville, 1st Earl of Westmorland
Lady Katherine Neville, Duchess of Norfolk
Lady Eleanor Neville, Countess of Northumberland
Richard Neville, 5th Earl of Salisbury
Robert Neville, Bishop of Durham
William Neville, 1st Earl of Kent
Edward Nevill, 3rd Baron Bergavenny
Lady Anne Neville, Duchess of Buckingham
Lady Cecily Neville, Duchess of York
George Neville, 1st Baron Latymer
Father John of Gaunt, 1st Duke of Lancaster
Mother Katherine Swynford
Born c. 1379, Château de Beaufort, Anjou
Died 13 November 1440, Howden, Yorkshire
Burial Lincoln Cathedral, Lincolnshire
Lady Joan Beaufort, Countess of Westmorland (c. 1379 \endash 13 November 1440) was the third or fourth child (and only daughter) of John of Gaunt, 1st Duke of Lancaster and his mistress, later wife, Katherine Swynford.
Early life and marriages
She was likely born at the Swynford manor of Kettlethorpe in Lincoln. Her surname probably reflects his father's lordship of Beaufort in Champagne, France, where she might also have born. In 1391, at the age of twelve, Joan married at Beaufort-en-Vallée, Anjou, Robert Ferrers, 5th Baron Boteler of Wem, and they had two daughters before he died about 1395.
Along with her three brothers, Joan had been privately declared legitimate by their cousin Richard II of England in 1390, but for various reasons their father secured another such declaration from Parliament in January 1397. Joan was already an adult when she was legitimized by the marriage of her mother and father with papal approval. The Beauforts were later barred from inheriting the throne by a clause inserted into the legitimation act by their half-brother, Henry IV of England, although it is not clear that Henry IV possessed sufficient authority to alter an existing parliamentary statute. Soon after this declaration, on 3 February 1397, when she was eighteen, Joan married Ralph de Neville, 1st Earl of Westmorland, who had also been married once before.
Source <The making of the Neville family in England, 1166-1400> Par Charles Robert Young:
"THE NEVILLE FAMILY (extract):
11. Ralph de Neville = (1) Margaret Stafford & = 2) Joan Beaufort (dau. of John of Gaunt)
12. Edward de Neville, Lord Abergavenny d. 1476 ..."
"... Pedigree of Gilbert. [For further information, see the overview chart of lineal ancestors of King Edward III of England and Philippa of Hainault , or the off-site hyperlinked genealogy of English and other royalty, with some annotations (proper names at or near the top of the following chart are linked to the second of these sources).]
1. Edward III, King of England born 13 Nov. 1312, Windsor, died 21 June 1377, London = Philippa of Hainault born about 1312, Hainault, Belgium, married 24 January 1327, died 14/15 August 1369, Windsor
2. John of Gaunt, born March 1340, mar. 20 Feb. 1397, died 3 Feb. 1398 = Catharine Roet, 3rd wife, born 1350, died 10 May 1403. (Her sister Philippa Roet married Geoffrey Chaucer, the poet.) They were great-great-grandparents of Henry VII (Tudor)
3. Joan de Beaufort, born ca. 1375 Beaufort, Anjou, died 13 Nov. 1440, Howden, Yorks = Ralph Neville, born 1364 Raby Castle, Durham, died 21 Oct. 1425
4. Edward Neville, born ca. 1412 = Catharine Howard (2nd wife)
5. Catharine Neville, born ca. 1450 = Robert Tanfield
6. William Tanfield, born ca. 1480 = Isabel Stavely
7. Catharine Tanfield = John Gilbert
8. William Gilbert, Vicar of Barton Turf = Ellen Furford
9. Ellen Gilbert, died 10 Jan. 1582 = Nicholas Wright, born ca. 1538, married 18 February 1559, died 1 October 1582."
Joan married Sir Ralph DE NEVILLE, Knt, 1St Earl Of Westmorland  [MRIN: 587], son of Sir John DE NEVILLE, Knt, 3Rd Baron Neville De Raby  and Mathilda DE PERCY . (Sir Ralph DE NEVILLE, Knt, 1St Earl Of Westmorland  was born about 1364 in Raby Castle, Durham, England and died on 21 Oct 1425 in , , England.)