“Cardinal Beaufort: A Study of Lancastrian Ascendancy and Decline” by G.L.Harriss
This 1988 volume reads very well and is an excellent summary of the life of the second (or first) son of John of Gaunt by his mistress Catherine de Roet. The language is very modern although the plain cover is a little reminiscent of many older books.
There is relatively little material about Henry Beaufort’s early years but he only became important as Bishop of Lincoln (from 1398) and of Winchester (translated in 1404), the latter occurring after the usurpation of his half-brother as Henry IV. During his forty-three years at the latter see, he was also to serve as Chancellor to the Lancastrian kings and lent the Crown many thousands of pounds to cover the costs of the French wars under Henry V and afterwards. He emerged as the head of his family and a player even among the legitimate Lancastrian circle, an ally of John of Bedford and rival of Humphrey of Gloucester.
As his brothers died and many of his nephews became hostages, Cardinal Beaufort became responsible for Edmund, later Duke of Somerset. Harriss details Edmund’s relationship with the widowed Catherine de Valois and makes a strong case (pp.144,177-8) for him having fathered at least one of her later children, taking facts such as her date of death – so the only two recent historians to analyse this have formed the same likely conclusion. He also note the 1427 law against Queens Consort remarrying.
Harriss also records Henry Beaufort’s promotion to the rank of Cardinal, his dealings with Martin V and other pontiffs together with the accusations of praemunire that Gloucester laid against him. Eventually, during Beaufort’s lifetime, Gloucester’s downfall followed his wife’s necromancy that led to her life imprisonment and the execution of several of her servants. It remains unclear whether the Cardinal played a part in this downfall whilst Harriss doesn’t mentionthe illegitimate daughter he is supposed to have had.
I would strongly recommend this book for borrowing, even without a genealogy of the Beauforts, although I wouldn’t spend a hundred and twenty pounds to buy it.