Tristan, who did not recognize him and hated him mortally because of the shield with the white lion that he saw him carrying, lowered his lance and charged towards him.

Hebes began to cry out, "Stop, Sir Tristan, stop!"

But he did not stop, and he struck Hebes so violently that he broke through his shield and hauberk and drove his lance through his chest, so that the point appeared on the other side, and he knocked Hebes to the ground so badly hurt that he needed no doctor.

Post-Vulgate Quest for the Holy Grail