« His sword carved his name across the continents - and his glory across the seas! »
In seventeenth century England, Irish Dr. Peter Blood is convicted of treason against the King for aiding a wounded friend who had participated in the Monmouth Rebellion. He is sentenced to slavery in the British colony of Port Royal, and is purchased by the beautiful niece of the local military commander Colonel Bishop, Arabella Bishop, who is attracted by his rebellious nature. During a Spanish raid on the town, Doctor Blood and his fellow slaves escape, steal the Spanish ship and begin a life of piracy. When the old governor is unable to contain the pirate menace, Colonel Bishop is promoted to his post.
Several years later, Arabella and a royal emissary, Lord Willoughby, are captured for ransom by Blood's treacherous partner, Captain Levasseur. Blood purchases them himself, relishing the opportunity to turn the tables on his former owner. However, Levasseur objects; in the ensuing duel, the Frenchman is killed.
Blood decides to take Arabella and Lord Willoughby to the safety of Port Royal. As they approach the port, they sight two French warships attacking the colony. Bishop and his men are nowhere to be found; Bishop has deserted his post in his single-minded hunt for Blood. Willoughby pleads with Blood to save the colony, but the captain and his crew to a man refuse to fight for James II of England. However, when Willoughby reveals that James II has been deposed in the Glorious Revolution and that he was sent by the new king, William of Orange, to offer pardons, emancipation, and a commission with the Royal Navy to Blood and his men, they joyfully change their minds at this good news.
Blood and his crew approach the harbor disguised under French colors and save the colony in a pitched battle. As a reward, Blood is appointed the new governor of the colony and has the pleasure to deal with his hostile predecessor, now in serious trouble for dereliction of duty, and finally wins the hand of Arabella.