Born in 1533 to Henry VIII and Anne Boleyn, Elizabeth Tudor was a lively, active child and, apart from teething problems as an infant, experienced robust health until adolescence. Despite the traumatic loss of her mother to the executioner’s sword while still a toddler, Princess Elizabeth showed no evidence of illness until puberty. Then, a series of disturbing events triggered a cycle of chronic ailments that overshadowed her teenage years. The death of her father in January 1547 precipitated a change in her abode and before long the princess found herself living with Henry’s widow, her stepmother Katherine Parr, and Katherine’s new husband, Thomas Seymour, at their house in Chelsea. Attractive to women, Thomas Seymour was the brother of Protector Somerset; he was also Edward VI’s younger maternal uncle, and Lord High Admiral after February 1547. Rumors joined his name to Elizabeth’s, but just five months after the king’s death, Seymour married the Queen Dowager, previously an object of his affections, in a secret ceremony. Seymour was jealous of his brother and conspired against him with John Dudley and others. Somerset initially opposed the hasty marriage of the Lord Admiral to Katherine, but was later reconciled to it by the young king, with whom Thomas had ingratiated himself.

According to depositions from members of the household at Seymour’s later trial, strange behavior characterized the interactions of the Seymours and their innocent, inexperienced guest, conduct that sometimes took the form of physical, semi-sexual frolics in the princess’ bedroom in the early morning hours. On one bizarre occasion in the garden of their residence at Hanworth, Seymour ripped Elizabeth’s dress while Katherine held her fast. After Katherine absented herself due to advancing pregnancy, the rough-housing between the Lord Admiral and Elizabeth sometimes got out of hand. Servants told Katherine that her husband made overtly lecherous advances towards Elizabeth, and Katherine herself may have caught them in an inappropriate embrace. The princess soon left the Seymours to stay with Sir Anthony Denny at Cheshunt in Hertfordshire, under the shadow of embarrassment and in the face of multiple complaints.

Elizabeth’s symptoms included migraine headaches, irregular menstrual periods, digestive problems, jaundice, and episodic anxiety attacks; she was ill throughout the summer of 1548 and into the fall.