At the start of Shakespeare's Richard II Bolingbroke and Mowbray, Duke of Norfolk, are called before the King ‘to appeal each other of high treason’. Each of the disputants is anxious to defend his honour and to prove the other a traitor in the lists. Before they come before him, Richard asks Gaunt if this dispute is based on ancient malice or ‘worthily, as a good subject should, on some known ground of treachery in him’. Gaunt replies that, ‘as near as I could sift him on the argument’, there is no inveterate malice, but apparent danger to the King. Richard responds:

Only after they have had their say and Richard and others have failed to persuade them to make up, does he reluctantly agree to let

They reassemble at Coventry ready for battle, but the King intervenes at the last moment to stop the fight and to banish both disputants, a classic example of a disastrous attempt at peaceful dispute-settlement.

We need not here concern ourselves with the detailed accuracy of Shakespeare's account of the proceedings, nor with whether this mode of dispute-settlement can appropriately be said to have involved a ‘trial’, political or otherwise.