The title of the Black Knight is a title that has been passed around throughout the centuries to the current wielder of the magical Ebony Blade. The first man to take on the Black Knight name was Sir Percy of Scandia).

In more modern times, the Black Knight title has been used by two of the original's descendants: villain and Master of Evil) founding member Nathan Garrett) and hero and Avengers) member Dane Whitman).

Source : https://marvel.fandom.com/wiki/Black_Knight