I copy-and-pasted this from a website called.. medievalchronicles.com... is that.. okay..?...

The Black Knight

The Black Knight is an ambiguous motif that exists in many Arthurian legends. In some cases, Black Knight is used to refer to a random knight who appears as a competitor to one of the Arthurian knights.

In other episodes, Black Knight is a disguise often taken up by Sir Lancelot to escape attention. The most notable reference to a Black Knight is the tale of Sir Morien. According to a 13th century narrative of King Arthurian legends, Morien is called a son of a Moorish princess and is named the Black Knight because of his African lineage.

The Black Knight as Sir Morien

Sir Agrovale, one of the Knights of the Round Table, set out to look for Sir Lancelot when he became lost. During his search in far-off lands, he came across a Moorish princesses whom be bedded. From this union, Sir Morien was later born. Agrovale abandoned the Moorish princess and his illegitimate son and returned back to King Arthur’s court. Arthurian legends state that when Morien grew up, he set out to seek his father and reached England on this quest.

The Black Knight and Sir Lancelot

In the version where Sir Morien is considered to be the Black Knight, a story is related about his confrontation with Sir Lancelot. According to this story, Sir Morien was pitted against Sir Lancelot as a teenager. The combat continued for a long-time and in this hand-to-hand combat, neither was able to overpower the other. Finally, Sir Gawain intervened and asked the two to stop fighting in the spirit of good knights who meet a fine adversary.

The Black Knight was a legendary Medieval Knight

The Black Knight and His Armour

Since the origins of Sir Morien are described to be Moorish in Arthurian legends, subsequent stories related to him state that he always wore North African armour, very different from the armour of other Arthurian knights. Even the shield he bore was said to be of a Moorish make and shape.

The Black Knight and His Appearance

Since Sir Morien was of an African descent and had black skin, he has been described to be of an exceptional appearance in Arthurian legends. One legend, for instance, repeatedly refers to his skin colour as an unusual feature. According to these sagas, Sir Morien was black throughout and only his teeth were white, which is an obvious fact for a person of a different skin colour but apparently a surprising fact for medieval authors. The legends further state that no one would have dared to face Sir Morien had he not called upon God in front of them and affirmed that he was not the devil. This exasperation of other knights over his appearance, the legends state, was also for the fact that he was exceptionally tall and very skilled in combat.