Láďo, ty jsi princezna!(1979)

Overview:

After her mother's death, Lada lives alone with her father, the king, who prefers to spend time with the ladies of the court and has no time for his daughter. And when she protests, he decides to marry her off. So Lada runs away disguised as a boy to a neighboring kingdom. Lada – or Láďa – enters the service, that is, the kitchen, of the young king. And because the young king is celebrating his eighteenth birthday, Lada attends his ball...