According to another version, Catherine did so on her own initiative. During the rebellion of the Dukes, the King's brothers, which erupted after the controversial marriage of the King and ended in the dethronement of King Eric XIV that same year, Catherine and her stepdaughters, the Princesses Sophia and Elizabeth, were with the King in the capital. According to the official statement given by Prince John after the deposition in 1569, they were placed under guard, prevented from leaving and placed under the threat of being presented to Tsar Ivan the Terrible of Russia as hostages. Eric XIV had made an alliance with Russia against Poland, and the Tsar had presented the demand that he should give him his Polish sister-in-law, the spouse of Prince John, Princess Catherine Jagellon, as hostage to use against Poland, and a Russian embassy was at the time waiting in Stockholm to bring Catherine Jagellon to Russia. Eric XIV felt forced to decline this demand because of international pressure, but had offered to replace his Polish sister-in-law with his stepmother and his two sisters. According to John, the relationship between the King and the Queen Dowager was bad at this point, as he had accused her of having financed the Danes during the ongoing Northern Seven Years' War and threatened not only to give her, his sisters and their ladies-in-waiting over to the Russians but also to burn them alive. It is unclear how much of this is true and what is propaganda from the later John III to excuse the deposition of his brother, but what ever the case, Queen Dowager Catherine and Princesses Sophia and Elizabeth left the court and escaped to join the rebellious Dukes after having been given a threat of some kind by the King, likely when they were told of their planned Russian captivity. One version said that they were permitted to take a boat trip and continued until the other shore, and another one that they took a walk in the town and continued to the city gate: in any case, when they had left town, they were joined by the spouse of Princess Sophia, Magnus II of Saxe-Lauenburg, who had been sent by the King to pursue his brothers, but who instead took the Queen Dowager and the Princesses to join the rebels. When Eric XIV was forced to extradite his adviser Jöran Persson, it is possible that Catherine had a say in his fate: many decades later, she was threatened by the son of Persson, who blamed her for his father's death.