Giafredi

In the Tristano Panciaticchiano, the brother of Mador of the Gate who was poisoned at Arthur’s court. Guenevere, who had hosted the feast at which he died, was accused of murder by Mador, but Lancelot championed her and she was exonerated.

The same character is called Gaheris in the Vulgate Mort Artu and Patrise in Malory.