The Tale of Tsar Saltan (1967)

Driven from the court by her sisters' scheming, the young Tsarina is thrown into the sea in a cask with her infant son. Surviving the storm-tossed voyage, the mother and her now magically-adult son land on a remote island where he falls in love with a Swan Princess in human form, and longs for reunion with his estranged father, Tsar Saltan. Merchants come to the island with news of the tsar, and the prince sends word back to him, but the sisters continue their campaign of lies and trickery to keep them apart.