E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
One of Charlemagnes paladins, taken captive at the battle of Roncesvalles. He fell to the lot of Marlotes, a Moslem, who offered him his daughter in marriage if he would become a disciple of Mahomet. Guarinos refused, and was cast into a dungeon, where he lay captive for seven years. A joust was then held, and Admiral Guarinos was allowed to try his hand at a target. He knelt before the Moor, stabbed him to the heart, and then vaulted on his grey horse Trebozond, and escaped to France.