What is the name of this cartoon movie?

I used to have this movie on a cassette as a child and I really want to find it again but I can’t remember the name. Plot:
There is a girl who pretends to be a boy in order to inherit the throne and become a prince. The movie ends when her uncle finds out she is actually a girl and kills her by pushing her off a cliff.
If someone maybe also remembers the movie and has watched it too as a kid it would really mean a lot if I managed to find it somehow