Set against the backdrop of the Spanish invasion of England during the reign of Elizabeth I, The Sea Hawk is a classic of the pirate genre. Sir Oliver Tressilian is betrayed by a jealous half-brother and forced to serve as a slave on a galley. He is liberated when the ship is hijacked by Barbary pirates. Sir Oliver joins the pirates, gaining the name "Sakr-el-Bahr" (the hawk of the sea), and swears vengeance against his brother. The book was the basis for The Sea Hawk, the popular 1940 Errol Flynn swashbuckler.