Minnie is locked away for not marrying a prince, but Mickey saves her.

Ye Olden Days

The princess is to wed the Prince against her wishes. When she refuses, the king locks her in the tower. Minstrel Mickey sees her and rescues her, making a rope from the clothes of lady-in-waiting Clarabell. The king spots them and prepares to chop off Mickey's head until Minnie intercedes. The king calls for a joust. Mickey wins and they live happily ever after.