she participated in the double wedding between the King and Karin Månsdotter and the Princess Sophia and Magnus II of Saxe-Lauenburg. In the procession to church, the Queen Dowager escorted the King's bride, while the second bride, the King's sister Princess Sophia, followed secondly with Princess Elizabeth, which was regarded an insult in matter of rank, as the marriage between the King and the commoner was regarded a scandal which was boycotted by the Dukes, the brothers of the King. There were reports, that the King had plans to have his brothers, as well as other enemies invited to the wedding, killed during the celebrations, but that the plans failed because Månsdotter warned the intended victims through Queen Dowager Catherine. 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