[a] Catherine's marriage was part of a plan to eventually place Henry V on the throne of France, and perhaps end what is now known as the Hundred Years' War.

Early on, there had been a discussion of marrying her to the Prince of Wales, the son of Henry IV of England, but the king died before negotiations could begin.

According to the financial accounts of her mother, toys and gifts befitting a French princess were purchased, including pet turtledoves for Catherine.

Catherine was still young and marriageable, a source of concern to her brother-in-law Humphrey, Duke of Gloucester, the guardian of her son.

Rumours abounded that Catherine planned to marry Edmund Beaufort, Count of Mortain, her late husband's cousin.

The Duke of Gloucester was strongly against the match, however, and the Parliament of 1427–8 passed a bill which set forth the provision that if the queen dowager remarried without the king's consent, her husband would forfeit his lands and possessions, although any children of the marriage would not suffer punishment.

Catherine lived in the king's household, presumably so she could care for her young son, but the arrangement also enabled the councillors to watch over the queen dowager herself.

Nevertheless, Catherine entered into a sexual relationship with Welshman Owen Maredudd Tudor, who, in 1421, in France, had been in the service of Henry V's steward Sir Walter Hungerford.

[13] While the death date is not in question, the cause is, with an equal number of records stating that she did not die as a result of childbirth, but entered Bermondsey Abbey, possibly seeking a cure for an illness that had troubled her for some time.

After her death, Catherine's enemies decided to proceed against Owen for violating the law of the remarriage of the queen dowager.

Edmund married Margaret Beaufort, a descendant of John of Gaunt who had consequently a distant but disputed claim to the throne; following the elimination by war of most other candidates, their son became King Henry VII.

Her tomb originally boasted an alabaster memorial, which was deliberately destroyed during extensions to the abbey in the reign of her grandson, Henry VII.