In sixteenth century Spain, King Philip II, desirious of conquering the world, dispatches his ambassador, Don Jose Alvarez de Cordoba, to England, the rocky island that stands in the way of his grand scheme. Accompanied by his beautiful niece Doña Maria, Don Alvarez sets sail for England, but as his galley approaches the coast, the boat is attacked and plundered by Captain Geoffrey Thorpe, the privateering leader of a band of intrepid British sea fighters who steal to replenish their country's depleted coffers. Meanwhile, in England, Queen Elizabeth listens to the debate between Sir John Burleson, who urges her majesty to build a fleet in order to defend England against the imperialistic Philip, and Lord Wolfingham, who reassures the queen that Spain represents no threat to England. When the queen protests that she has no money with which to build a fleet, Geoffrey, who is in agreement with Sir John, confides in her his plan to rob the Spanish treasure hunters in Panama. After the queen grants Geoffrey her implicit consent, he readies for his voyage to Panama, but before leaving, meets Doña Maria in the garden and the two fall in love. Meanwhile, Don Alvarez and Wolfingham learn of Geoffrey's plan and dispatch Captain Lopez to stop him, and upon arriving in Panama, Geoffrey and his men are captured and condemned to be galley slaves. Just as Don Alvarez announces Geoffrey's demise and presents Elizabeth with an ultimatum of disbanding her fleet or facing war with Spain, Geoffrey learns that the Spanish Armada is poised to attack England. At Cadiz, he leads a mutiny of the slaves, commandeers a Spanish ship and arrives in England with proof of Spain's treachery. Geoffrey's warning saves England, and after his joyous reunion with Doña Maria, his queen knights him for his valor.
