Being a girl, daughter of a minor and somewhat impecunious Lincolnshire knight claiming descent back to the Saxons, no one thought it sufficiently important to make note of Blanche Swynford’s date of birth. Of course, History reveals little Blanche to be the god-daughter of John of Gaunt and daughter of Katherine Swynford. Nor for that matter is History terribly sure about the number of her sisters.

Historians are uncertain whether Blanche is older or younger than her brother Thomas who was born on 21 September 1368.  Anthony Goodman argues that Blanche was born sometime in 1366 whilst John of Gaunt’s first wife was still alive.  It makes sense that if Gaunt was her godfather that Blanche of Lancaster may well have been her godmother.  Equally it is possible to argue that the baby was named after the late duchess and not born until 1370 (ish).  Both scenarios are equally valid although there may be some shifting in the dates depending on the text.

Weir suggests that Blnache may have been born earlier given that Hugh inherited his estates in 1361 pushing the marriage date for Katherine and Hugh back to the start of the decade, at a point where Katherine would have only just attained a legally marriageable age, rather than placing it sometime between 1366 and 1367 as is usual.  In part the problem arises because Historians are uncertain whether Katherine married at a very young age or not.  The argument often given is that it seems unlikely that a very young woman would have been made governess of Gaunt’s children.

What we can be certain about is that the papal dispensation for the marriage between John of Gaunt and Katherine Swynford mentions Blanche because of the relationship that being godparent created.  There is also some evidence to suggest that Blanche grew up with John’s daughters – which makes sense given that Katherine was their governess- and which Weir uses as evidence of Katherine being married by the end of 1362 with Blanche making an arrival the following year.  The fact that Blanche is in Gaunt’s records as being in the household of his daughters in 1368 helps this viewpoint.

She turns up again in the aftermath of Queen Philippa’s death on 14 August 1369.  Edward III provided mourning for the ladies at court and Blanche as lady-in-waiting or more accurately demoiselle to John of Gaunt’s daughters received suitable garb for the occasion.  Weir argues that the mourning given to the Swynford family at this time reflects the fact that Philippa remained fond of Katherine and  Philippa Chaucer after their years growing up in the queen’s household.

Lucraft identifies the fact that Gaunt takes an active interest in his godchild.  Katherine was awarded the wardship of Robert Deyncourt in 1375 specifically to cover Blanche’s dowry. Of course, one of the key factors of having a wealthy ward was to marry him into the family as soon as decently possible.  Weir writes that Gaunt intended Deyncourt, a scion of the Lancaster Affinity, as a groom for his godchild. However – Blanche did not marry Robert.

Did she die young? Was Blanche dead by 1378? Possibly.  Alternatively the records provide us with another possible groom in the form of Sir Thomas Morrieux – the gift Gaunt gave the happy couple was extremely generous including as it did silver spoons, saucers and a basket with a silver top. The difficulty is that this may be a different Blanche. Froissart says that Morrieux’s wife was Gaunt’s illegitimate daughter. Either Froissart thought Blanche Swynford was Gaunt’s; or she was the daughter of Marie de St Hillaire or Froissart was wrong (his chronicles do contain errors). The evidence that this particular Blanche is Blanche Swynford is circumstantial- Morrieux was a Lancastrian retainer with an annuity of £100 p.a who died in Spain. Our lack of knowledge about his wife reflects the difficulty of decoding the past where records are incomplete and names not always terribly helpful.

The difficulties of working out relationships from fragmentary evidence and deductions without necessarily knowing exact dates for events are summarised by Sydney Armitage-Smith writing in 1904 about John of Gaunt:

But the attempt to identify the Duke s daughter and the daughter of his later mistress breaks down hopelessly. (It was made by Sir N Nicolas, Scrope v Grosvenor Con
troversy 11 185) For (i) there is Froissart’s explicit state ment quoted above ; (11) Blanche is never mentioned among the Beauforts , (ui) there is the insuperable difficulty of age.
Katharine Swynford, born in 1350, and married to Sir Hugh Swynford m 1367, whose elder child, Sir Thomas Swynford, was born in 1368, could not possibly have been the mother of Blanche, who was married to Sir Thomas Moneux in 1381.

https://archive.org/stream/johnofgaunt001003mbp/johnofgaunt001003mbp_djvu.txt

Lucraft, Jeannette. (2006) Katherine Swynford: The History of a Medieval Mistress. Stroud: Sutton Publishing

Weir, Alison. (2007) Katherine Swynford:The Story of John of Gaunt and his Scandalous Duchess. London: Random House