Who is Red Knight from Arthurian Romances and what is their importance?

The Red Knight is described as a haughty man, who offends King Arthur and Queen Guinevere before Perceval arrival. He spills his wine on the queen, and he steals the king's cup. Perceval, on the other hand, covets the knight's red armor and defeats him by throwing a javelin through his eye and brain. Perceval then returns the King's cup to its owner.