Don Sancho Martin, the Green Knight

Don Sancho Martin: The real life historical Green Knight: Sancho Martin Defender of Tyre 1187, available both mounted and dismounted

From "William of Tyre", a contemporary chronicler

"Not a day passed without the Christians making two or three sallies against the Saracens. They were led by a knight from Spain who was in the city of Tyre named Sancho Martin. He bore arms vert. When this knight issued forth, the Saracens all rushed up, more to see his fine bearing than for anything else. The Turks called him the Green Knight. He bore the antlers of a stag on his helmet, and this greatly befitted him.”

From Wikipedia:

"All of Saladin's attacks failed, and the siege dragged on, with occasional sallies by the defenders, led by a Spanish knight named Sancho Martin, better known as the "green knight" due to the colour of his arms. His bravery and skill were said to cause admiration in both the Christian and Muslim armies, and particularly in Saladin. It was said that Saladin offered him many riches if he would convert to Islam and fight in his army. Nevertheless, he refused and kept leading the Christian attacks against the Muslim army