When King Mark heard and understood how Sir Sadok and Sir Dinas were arisen in the country of Liones he remembered of wiles and treason.

Lo thus he did: he let make and counterfeit letters from the Pope, and did make a strange clerk to bear them unto King Mark; the which letters specified that King Mark should make him ready, upon pain of cursing, with his host to come to the Pope, to help to go to Jerusalem, for to make war upon the Saracens.
When this clerk was come by the mean of the king, anon withal King Mark sent these letters unto Sir Tristram and bade him say thus: that an he would go war upon the miscreants, he should be had out of prison, and to have all his power.

When Sir Tristram understood this letter, then he said thus to the clerk: Ah, King Mark, ever hast thou been a traitor, and ever will be; but, Clerk, said Sir Tristram, say thou thus unto King Mark: Since the Apostle Pope hath sent for him, bid him go thither himself; for tell him, traitor king as he is, I will not go at his commandment, get I out of prison as I may, for I see I am well rewarded for my true service.

Then the clerk returned unto King Mark, and told him of the answer of Sir Tristram.

Well, said King Mark, yet shall he be beguiled.