Fantaghirò: Cave of the Golden Rose (1991)

The king desires nothing more than a male heir. But his wife gives birth to a girl Fantaghiró. When she refuses to marry years later, she is sent in the forest where she learns how to ride and fight like a man. She appears disguised in a duel with Prince Romualdo, the son of her father's adversary. Both fall in love, but their marriage brings no peace to the united kingdom. Evil forces are trying to seize power.