Wizard v. Danish champions, for truage of the Slavs.
"The Danish History, Books I-IX" by Saxo Grammaticus ("Saxo the Learned")
How twelve aged ambassadors of Rome came to King Arthur to demand truage for Britain.
"Le Morte D'Arthur, Volume I (of II)" by Thomas Malory
And if that he might slay King Mark's knight, he to have the truage of Cornwall yearly.
"Le Morte D'Arthur, Volume II (of II)" by Thomas Malory