In 1587, England is in danger of being overwhelmed by powerful Spain, with its ruthless inquisition and mighty Armada. The English queen, Elizabeth, who is much loved by her loyal subjects, is forced to walk a dangerous diplomatic line between maintaining friendship with King Philip of Spain and supporting English seamen such as Sir Francis Drake, who plunder Spanish ships. Elizabeth's chief advisors are the lord treasurer, Burleigh, and her longtime admirer, the Earl of Leicester. Burleigh's beautiful but featherbrained granddaughter Cynthia is one of Elizabeth's ladies-in-waiting, and the aging queen is plagued with jealousy of the girl's attractiveness and vitality. While Elizabeth is dealing with the Spanish ambassador in her palace, a mighty sea battle is occurring between the Spanish, led by Don Miguel, and the English, led by Sir Richard Ingolby. Miguel and Richard are old friends, and when the English are captured, Miguel arranges for Richard's son Michael to escape. Michael washes ashore on Miguel's estate, and his wounds are tended to by Miguel's daughter Elena, who quickly becomes enamoured of the handsome Englishman. As the months pass, Michael recovers and laments being apart from Cynthia, his sweetheart, but is nonetheless impressed by Elena's charms. One day, the idyll ends when Miguel brings Michael the sad news that Richard has been executed as a heretic. The grieving Michael denounces his rescuers and flees to England in a small fishing boat. When he is granted an audience with Elizabeth, he urges her to fight the Spanish menace by whatever means necessary and swears undying loyalty to her. Elizabeth is flattered by the young man's fervent devotion and later has an opportunity to take advantage of his offer of service when Hillary Vane, an Englishman spying for Spain, is killed before the names of his English co-conspirators can be uncovered. Michael, disguised as Vane, goes to Philip's court to get the letters that will set into motion a plan to assassinate Elizabeth. At the palace Michael meets Elena, who is now married to Don Pedro, the palace governor. Elena keeps Michael's identity a secret as long as she can, but finally must tell her husband out of loyalty to him. When Philip sees through Michael's disguise and orders his arrest, Pedro helps him escape so that it will not be discovered that his wife aided a heretic. While Michael is returning home, the Spanish Armada sails against England and Elizabeth joins her army in Tilbury. Michael meets her there and reveals the names of the traitors. Elizabeth knights Michael and then confronts the traitors, who, overwhelmed with shame, agree to go with Michael on a dangerous mission to stop the Armada. The mission is successful as Michael and his men use their small boats to set the Armada aflame, and they all return safely. Elizabeth allows Michael and Cynthia to be wed, and after sadly ordering all mirrors to be removed from her rooms, greets her adoring subjects.