Vadstena Rumble

Then the ladder was removed, and the princess's courtier and some other gentlemen rushed into Cecilia's chamber and seized Johan, according to Erik's letter to his brother, in his shirt, barely wearing his trousers.

[5] In the letter, Erik continues:[5] “And although we could not think that what he had entered there had been done for the sake of our sister, but rather for the sake of some maiden who was lying there, a suspicion was nevertheless given to us; and since we knew well before that her Love had much to order with the Count Johan both in conversation and socializing — although we had often discouraged her love from that before —, we conceived something else, wherefore we could not suffer such arrogance of his but immediately had him adopted and sent well cared for to the King's Majesty, our dear father.„Johan was thrown into prison and according to tradition he is also said to have been castrated on Duke Erik's orders.

King Gustav Vasa blamed his son Duke Erik for letting the story spread to the "common" people instead of just throwing Johan of East Frisia into the dungeon and then not talking about it again.

[5] The king severely rebuked his son for his actions: he had treated his own sister "like a clear harlot" and thrown Count Johan into prison.

The release took place a week before Gustav Vasa's death, after repeated prayers by Johan's relatives and several German princes, and after the count swore that nothing had happened between him and the king's daughter that was against discipline and honor.

[6] Due to the complications and the fact that her father Gustav Vasa died in September 1560 and was buried in December of the same year, Catherine was forced to stay in Sweden until 1561 before she could travel to East Frisia.