Geoffrey Thorpe (Errol Flynn) is a privateer under the command of Queen Elizabeth (Flora Robson), raiding the Spanish treasure fleet for the honor and wealth of England. On one of the Spanish ships he captures, he comes into contact with Doña Maria (Brenda Marshall), a hot blooded Spanish noblewoman and takes her personal jewel box. To show her that he isn't the monster she thinks he is, Thorpe returns Maria's jewels to her and goes a long way towards winning her heart. However when he returns to England trouble awaits due to intrigue in the court,King Phillip II (Montagu Love) of Spain has sent Don José Alvarez de Cordoba (Claude Rains) to negotiate with Queen Elizabeth and Thorpe is now out of favor. But Cordoba is really plotting with Lord Wolfingham (Henry Daniell), as the Spanish Armada waits to sail. Will Thorpe win the day and his ladies heart?