Just some Wiki for everyone who might be interested.
“Il Corsaro Nero” is the title of the novel which the movie was inspired from.
In Italy “The Black Corsair” is an iconic character. He’s THE pirate, even for people who didn’t read Salgari’s book. Many movies were based upon that novel.
I think they changed the international title because they thoght that the reference to Salgari might have been too obscure… I’m quite confident the only Salgari’s character who’s really globally famous is Sandokan.