Claiming the young noblewoman for himself, instead of marrying her to his son as he had originally claimed to intend, the two wed just three months after his wife's death. At this turn of events, Katherine's life changed dramatically. As her husband was one of the king's closest friends, she now spent much of her time at court in Henry VIII's presence - even supposedly catching his eye with her beauty and charm (as a claim from 1538 states). She gave the duke two sons - Henry and Charles (the former becoming the second Duke of Suffolk when Charles Brandon died in 1545.
Over time, the formerly-raised Catholic Katherine turned reformist in belief, supporting King Henry's break with Rome, attending Hugh Latimer's sermons at Hampton Court, and become outspoken about reform. When the king married his sixth wife, Catherine Parr, the now-Dowager Duchess of Suffolk became close with her - even helping to fund the publication of the Protestant queen's book, Lamentations of a Sinner in 1547.
Tragically, Katherine's own sons succumbed to the sweating sickness of 1551. While they had fled their studies at St. John's College, University of Cambridge, to avoid the contagion, they died within half an hour of each other at Katherine's rented house in Buckden. Katherine had not arrived in time to say a proper goodbye to either of them - as the eldest, Henry, had died before she got there, and Charles had already drifted into unconsciousness - dying within minutes of her arrival.
In 1552, Katherine married once again - but this time, for love. Richard Bertie served as her Gentleman Usher prior to their wedding, and the couple had a daughter named Susan in 1554 - soon after Queen Mary's ascension to the throne. As previously stated, Katherine had become a staunch Protestant during her years at court, so now that a Catholic queen ruled England (and swiftly began persecuting reformers), Katherine and her family chose to flee for the continent - preferring to live in exile and poverty rather than risk the ugly fate of a Protestant in Marian England. While in exile, Katherine gave birth to a son named Peregrine in 1555. Once Queen Mary died in 1558, the family determined that it was safe to return to England.
Throughout the rest of her life, Katherine devoted herself to advocating for the Protestant cause, and many books written on reform during the latter-part of the sixteenth century were dedicated to her or bore her coat of arms. England had not become the Protestant utopia that Katherine and Richard had hoped it would be under Elizabeth I (and their troubles were far from over open returning home), but they managed to avoid arrest and execution (perhaps narrowly) for their outspoken religious beliefs.
- Baldwin, David, 'Katherine Willoughby, the Lincolnshire Lady who nearly married Henry VIII' (Lincolnshire Life).
- Riches, Tony, 'Understanding the Life of Katherine Willoughby, Duchess of Suffolk' (Guest post - On The Tudor Trail).