Henry VIII died in 1547; Elizabeth's half-brother, Edward VI, became king at age nine. Catherine Parr, Henry's widow, soon married Thomas Seymour of Sudeley, Edward VI's uncle and the brother of the Lord Protector, Edward Seymour, Duke of Somerset. The couple took Elizabeth into their household at Chelsea. There Elizabeth experienced an emotional crisis that some historians believe affected her for the rest of her life. Seymour, aged in his early 40s but having charm and "a powerful sex appeal", engaged in romps and horseplay with the teenage Princess Elizabeth. These included entering her bedroom in his nightgown, tickling her and slapping her on the buttocks. Parr, rather than confront her husband over his inappropriate activities, joined in. Twice she accompanied him in tickling Elizabeth, and once held her while he cut her black gown "into a thousand pieces." However, after Parr discovered the pair in an embrace, she ended this state of affairs. In May 1548, Elizabeth was sent away.
However, Thomas Seymour continued scheming to control the royal family and tried to have himself appointed the governor of the King's person. When Parr died a few days after childbirth on 5 September 1548, he renewed his attentions towards Elizabeth, intent on marrying her. The details of his former behavior towards Elizabeth emerged, and for his brother and the council, this was the last straw. In January 1549, Seymour was arrested on suspicion of plotting to marry Elizabeth and overthrow his brother. Elizabeth, living at Hatfield House, would admit nothing. Her stubbornness exasperated her interrogator, Sir Robert Tyrwhitt, who reported, "I do see it in her face that she is guilty". Seymour was beheaded on 20 March 1549.