Count Adhemar is the main villain of the 2001 Medieval Action movie, A Knight's Tale.
He was played by Rufus Sewell.
Rival in the joust and for Jocelyn's heart as well. Adhemar defeats William in the final joust of the tournament. In the next tournament, Adhemar and William, the 2 of them, are assigned the tilting of Sir Thomas Colville, but in fact he's really Edward, The Black Prince. Adhemar withdraws while William continues the match.
Adhemar goes to the battlefield and then makes his arrival in London and talks to Jocelyn's father about marrying her. Later Adhemar discovers William with his father and alerts the authorities and has William put in a pillory. But thanks to William's friends and Prince Edward, who knights him Sir William, Sir William returns to confront Adhemar once and for all. But Adhemar cheats by pierceing William's shoulder and hurting him very badly, with an illegal sharpened lance.
William loses by 2 lances and has got to unhorse Adhemar to beat him. So Sir William requests to be stripped of his armor and Chaucer buys time for him you know. Sir William tilts against Adhemar and with a crushing blow knocks the count to the ground and defeats him.