Sir Thomas Palmer, who had all along acted as a spy upon Somerset, accused him of having formed a design to raise an insurrection in the north, to attack the gens d'armes on a muster day, to secure the Tower, and to raise a rebellion in London: but, what was the only probable accusation, he asserted, that Somerset had once laid a project for murdering Northumberland, Northampton, and Pembroke at a banquet which was to be given them by Lord Paget Crane and his wife confirmed Palmer's testimony with regard to this last design; and it appears that some rash scheme of that nature had really been mentioned, though no regular conspiracy had been formed, or means prepared for its execution Hammond confessed that the duke had armed men to guard him one night in his house at Greenwich.
Somerset was brought to his trial before the marquis of Winchester, created high steward.

Twenty-seven peers composed the jury, among whom were Northumberland, Pembroke, and Northampton, whom decency should have hindered from acting as judges in the trial of a man that appeared to be their capital enemy.

Somerset was accused of high treason, on account of the projected insurrections, and of felony in laying a design to murder privy counsellors.
We have a very imperfect account of all state trials during that ago, which is a sensible defect in our history; but it appears that some more regularity was observed in the management of this prosecution than had usually been employed in like cases.

The witnesses were at least examined by the privy council; and though they were neither produced in court, nor confronted with the prisoner, (circumstances required by the strict principles of equity,) their depositions were given in to the jury.

The proof seems to have been lame with regard to the treasonable part of the charge; and Somerset's defence was so satisfactory, that the peers gave verdict in his favor: the intention alone of assaulting the privy counsellors was supported by tolerable evidence; and the jury brought him in guilty of felony.