Anne of the Indies (1951)

After seizing an English ship, buccaneer captain Anne Providence spares Pierre LaRochelle from walking the plank - as he's in irons he is presumably no friend of England. He signs on as a pirate and she is increasingly drawn to him, a feeling that seems to be reciprocated. When fearsome Captain Blackbeard, her teacher in the ways of pirating, sets eyes on LaRochelle he recalls him as a French navy officer. Anne sticks by her man but the truth, when it is uncovered, is even more painful.