Thomas Seymour, one of Edward VI's uncles, died on the block on March 20, 1549 at the age of 41. He left a baby daughter, Mary, whose mother, Catherine Parr (Henry VIII's last wife) had died in childbirth. Seymour was the 1st Baron Seymour of Sudeley and had been Lord High Admiral of England, but he was accused of treason against Edward VI. Seymour's brother was Lord High Protector, Edward Seymour, 1st Duke of Somerset, who would also die at the block during Edward's reign.
The young Princess Elizabeth had lived with Parr and Seymour for a time after Henry VIII's death, but was removed from the household after Catherine Parr noticed the untoward behavior of Seymour toward Elizabeth. Lady Jane Grey was also in their care and she was in the household when Parr gave birth to her only child, Mary; this was her fourth marriage. Parr died after Mary's birth (surely named after the Princess Mary?).
This orphaned baby was placed in the care of Katherine Willoughby, the widow of Charles Brandon, the Duke of Suffolk (who had married Henry VIII's younger sister Mary). Although Katherine Willoughby was of Spanish descent--her mother was one of Catherine of Aragon's ladies-in-waiting and best friends--she was not a Catholic, but favored the Protestant cause. And, although she was friend of Catherine Parr's, Katherine did not appreciate being the guardian of this little baby girl.
Linda Porter writes about Seymour's fall and the fate of his little girl in this History Today article:
Despite her strong religious views, the duchess’s bosom was not full of Christian charity. Lady Mary may have been a dispossessed orphan, but she was an expensive one. As a queen’s daughter, she came with a household of her own, consisting of a lady governess, rockers, laundresses and other servants. The government was supposed to provide for her upkeep and the payment of her staff but the duchess could not get Somerset to part with the money until she appealed to William Cecil, then a prominent member of the duke’s household, to intervene on her behalf. The letter she wrote makes it clear how much she resented ‘the queen’s child’, as she frostily referred to the little girl.
The article concludes with what might have been the child's epitaph:
Of her own life
My queenly mother
Bore with the pangs of labour
Sleep under this marble
An unfit traveller.
If Death had given me to live longer
That virtue, that modesty, That obedience of my excellent Mother
That Heavenly courageous nature
Would have lived again in me.
You are, fare thee well
Because I cannot speak any more, this stone
Is a memorial to my brief life
Read the rest here.