On November 7, 1683, Algernon Sidney demanded first that he might look upon the indictment that imperilled his life. The bench denied him. Standing at the bar, the Colonel had just heard read an accusation combining diverse overt acts: compassing the death of Charles II, levying insurrection, soliciting confederates in Scotland, and asserting in writing that the people might resume the authority delegated to their sovereign. Sidney protested that these charges were distinct in law and that he could scarce answer a bill he was forbidden to inspect. The Lord Chief Justice, George Jeffreys, bade him plead directly to the matter or submit an exception in due form. Sidney sought the aid of counsel and an adjournment. Following this sharp altercation, he was constrained to enter a plea of “Not Guilty.” The court assigned the trial for a fortnight thence.
When he returned on November 21, Sidney had transcribed a statutory text and once more petitioned for a copy of his indictment. He maintained that the law of the realm secured him this right; the judges answered that it did not. He further moved for counsel, yet the court granted legal aid solely to such as could first formulate a point of law deemed by the bench worthy of argument. Thus the proceeding opened upon a dispute of procedure: Sidney averred he was stripped of the means necessary to his defense, whilst Jeffreys represented these severities as the ordinary rules governing any prisoner accused of high treason.
The case for the Crown began with men who had heard whispers of an impending rising, though none possessed direct personal knowledge of Sidney. Rumsey related what he had gathered from West and Goodenough: that a select council of six had joined the Duke of Monmouth, the Earl of Essex, Lord Howard, Colonel Sidney, Hampden, and Lord Russell. He knew that other conspirators treated of Scotland, yet he was forced to concede that West was far better acquainted with those particular transactions than himself. Keeling stated that Goodenough had furnished him with papers designed for the ordering of confederates, and that Sidney’s name had been mentioned in connection with the enterprise; he acknowledged, however, that he had never seen the Colonel.
The cornerstone of the Crown’s case lay in the deposition of Lord Howard, one of the men he placed at the very heart of the conspiracy. He testified that toward mid-January, following the collapse of an earlier design, Monmouth, Sidney, and himself had agreed to assemble a select cabal. Monmouth was to approach Lord Russell and Salisbury; Sidney was tasked with securing Essex and Hampden. Howard affirmed he had assisted at a meeting at Hampden’s lodgings, and later at another under Lord Russell’s roof, wherein they debated how best to unite the English disaffected with the Scottish factions. He could assign no precise dates, though he professed to recall the season, the persons gathered, and the themes of their colloquies.
According to Howard, Sidney had proposed Aaron Smith as their messenger and had taken upon himself the charge of his dispatch. Howard swore he saw him produce some threescore guineas, affirming they were intended for Smith’s purse, though he could not avow whether they had ever passed into the man’s hands. As for the northern journey, Howard averred he held his intelligence largely from Sidney himself, who allegedly recounted thereafter that Smith had advanced as far as the neighbourhood of Newcastle. The prosecution added that several gentlemen of North Britain—Sir John Cochrane, the Campbells, and Commissary Monro—had repaired to London under colour of private affairs in Carolina, only to abscond when the plot was broken. The Attorney-General urged their sudden arrival and movements as material presumptions confirming the treason.
A second branch of the indictment arose from a writing-cabinet. In late June, Sir Philip Lloyd, bearing a warrant from the King and the Privy Council, had searched Sidney’s dwelling. He declared he found diverse papers upon a table, in the chamber where the Colonel was wont to write. Lloyd offered to allow Sidney to affix his own seal upon the chest to obviate any suspicion of tampering; Sidney refused. The magistrate thereupon sealed the trunk himself and had it conveyed to the Secretary of State’s office. At the trial, he identified among these sheets an extended political treatise.
Three witnesses were brought forward to swear to the handwriting. Sheppard had seen Sidney subscribe endorsements upon bills of exchange. Carey and Cooke had never seen him draft the treatise, but compared the loose sheets with endorsements and signatures already known to them. All declared the script to be of the same hand as Sidney’s. The Crown officers caused long passages to be read aloud, wherein the author debated the sovereignty of the people, the limits hedging kingship, and the lawful right of resistance. In the eyes of the prosecution, these leaves laid bare the guiding principle of the insurrection outlined by Howard. For Sidney, the hand remained unproven, and the mere presence of unprinted pages in his closet established neither when they had been set down nor for what purpose.
Sidney proceeded to attack the thread binding these proofs together. He urged that Howard stood entirely alone in swearing to his presence at the cabals. The remaining witnesses, he argued, had deposed only to a general tumult, or reported hearsay gleaned from third parties. The statute, he insisted, required two lawful witnesses to establish the same overt act of treason; the Crown could not conjoin a contested assembly with an undated manuscript to forge the body of a single crime. He likewise repelled the doctrine that a private, speculative discourse upon the deposition of a monarch could be made equivalent to compassing his physical destruction.
The defense summoned several men of honour to impugn Howard’s veracity. The Earl of Anglesey testified that, ere he turned Crown witness against Sidney, Howard had assured the aged father of Lord Russell that his son was upright, that he believed him untainted by any treasonable design, and that he knew of no bloody enterprise. Lord Clare declared he had heard him extol Sidney’s spotless innocence. Philip Howard related that his kinsman had at first treated the entire conspiracy as an absurdity and an invention. Doctor Burnet affirmed that on the morning following the discovery, Howard raised his hands to heaven, swearing that he knew nothing of the affair and held it altogether preposterous. These testimonies set in stark contrast Howard’s oath at the bar and his repeated previous disavowals.
Following the final argument of the Solicitor-General, Jeffreys delivered the charge on behalf of the court. He set forth the law as he construed it, marshalled the Crown’s proofs, and turned to Sidney’s exceptions and Howard’s credibility. The prior denials of the witness did not appear to him to subvert his oath: an accomplice in a treasonable plot would naturally conceal what he knew until his conscience was moved. As for the treatise, the Chief Justice coupled it directly with the project of insurrection described by the witnesses. The speculative doctrines attributed to Sidney served, in this construction of the law, as the living spring and confirmation of the councils held behind closed doors. Jeffreys concluded by leaving the jurors to determine whether the treason had been sufficiently proved. Ere they withdrew, Mr. Justice Wythens added that, but for Keeling’s discovery, God alone knew whether any of them would yet be among the living. The jury retired; within half an hour, they returned to find Sidney guilty.
On November 26, Sidney was brought up to receive his judgment. He once more objected to the panel of the jurors, praying that his exceptions might be heard; the court replied that he ought to have challenged them ere they were sworn. The sentence decreed by the law for high treason was to be hanged, drawn, and quartered. Sidney answered with a prayer: if his innocent blood were to be avenged, let the guilt fall entirely upon those who had brought him to this pass. The King remitted all the penalties of his sentence save that of decapitation. Borrow records that Sidney was conducted to a scaffold upon Tower Hill and there beheaded.