Edgar Rice Burroughs 
Outlaw of Torn 

The story is set in 13th century England and concerns the fictional outlaw Norman of Torn, who purportedly harried the country during the power struggle between King Henry III and Simon de Montfort. Norman is the supposed son of the Frenchman de Vac, once the king’s fencing master, who has a grudge against his former employer and raises the boy to be a simple, brutal killing machine with a hatred of all things English. His intentions are partially subverted by a priest who befriends Norman and teaches him his letters and chivalry towards women. (Wikipedia)