Seymour and Catherine Parr became romantically involved after the death of her second husband, but then King Henry took an interest in Catharine, and Seymour had to step aside. Catherine became Henry's sixth wife. After he died, she married Seymour (brother of Henry's third wife Jane) in unseemly haste. She became pregnant, gave birth to daughter Mary, and died a few days later.
Thomas (the Lord High Admiral) and his brother Edward (the Lord Protector of England) wielded great power in England, through their nephew King Edward VI of England who was still a child when he came to the throne.
Thomas was overly ambitious and wanted to marry his nephew's half-sister Princess Elizabeth, later Elizabeth I of England. His sexual misconduct with her while she lived with the Seymours and forced her stepmother Catherine to send her away for her own protection. Thomas was eventually executed for over-reaching in the power game, he tried to wrest control of young Edward the king from brother Edward and Edward had him executed.
Catherine's daughter Mary should have been a wealthy woman, but her mother had left her fortune to her husband. When Thomas was executed, the crown confiscated everything he had, including Catherine's bequest. The child appears to have died around the age of two, when she disappears from historical record.
