William des Preaux
From Tardis Wiki, the free Doctor Who reference
William des Preaux was a knight who served under King Richard I of England during the Crusades.
When El Akir ambushed them outside Jaffa in 1190, William claimed to be Richard to save his king. El Akir took Barbara Wright and him to Saladin's encampment at Ramlah. Des Preaux protected Barbara and suggested that she pretend to be Joanna, sister of the king. However, Saladin saw through William's imposture. When Ian Chesterton visited Saladin, he tried to arrange for des Preaux's release, but Saladin refused. (TV: The Crusade)