The Sea-Hawk.

The Sea Hawk is a novel by Rafael Sabatini, originally published in 1915. The story is set over the years 1588–1593, and concerns a retired Cornish sea-faring gentleman, Sir Oliver Tressilian, who is villainously betrayed by a jealous half-brother. After being forced to serve as a slave on a galley, Sir Oliver is liberated by Barbary pirates. He joins the pirates, gaining the name "Sakr-el-Bahr", the hawk of the sea, and swears vengeance against his brother.