The Lord Chief Justice refused to have anything to do with the idea; nor would his senior colleagues. Even eminent lawyers friendly to the Government advised moderation. In the end a junior judge who, two years earlier had publicly described the Head of State as "worse than Nero" was appointed.
The jury was in effect 135 members of the House of Commons, called commissioners for the purpose. Members of the House of Lords were excluded because of their opposition. It was early decided that only the presiding judge and counsel would be allowed to speak. The commissioners would have to stay silent. They could pass such questions as they might have to the presiding officer.
By mid-month, the authorities had become thoroughly alarmed about security. Everybody remembered serious incidents not many years before. They decided that the Head of State would be accommodated close to Westminster Hall and would be guarded by 200 soldiers; a further 1,000 men would be constantly on duty. All entrances would be under military control.
The most difficult problem, however, was to draw up the charges. They were finally settled on the day before the trial began. It was claimed that the Head of State had attempted to "erect and uphold in himself an unlimited and tyrannical power, to rule according to his will and to overthrow the rights and liberties of the people". Many alleged examples were given and the defendant was finally denounced as "a tyrant, traitor, murderer and a public and implacable enemy".
No doubt the framers would have liked to have included charges relating to religious policy, but they forbore to do so.
On the morning before the trial was due to commence in the afternoon of 20 January, the commissioners were so nervous that they held a private session to rehearse "forms and methods". What, they wondered, would be the demeanour of the Head of State? Would he be insolent or contemptuous?
More seriously, if the court was asked by what authority it was established, what answer should be given? No wonder the presiding judge asked that two lawyers should be seated close to him to provide advice. Then, when the trial finally began, it was found that only 68 of the 135 commissioners were present. Absence was a form of mute protest.
There was trouble immediately. When a roll call of the commissioners was taken, there was an interruption from the public gallery. The wife of the first person named called out that her husband had more sense than to be present. Then the Head of State was brought in. Nothing in his expression showed any interest in what was going on, nor any recognition of those present.
But when he was required to answer the charges, he asked the question the commissioners had feared. "By what power am I called... let me know by what lawful authority I am seated here, and I shall not be unwilling to answer".
The judge then gave the reply which had been worked out in the morning, saying "in the name of the people." The Head of State responded that he saw no presence from the House of Lords, which would be necessary to form a Parliament. The exchanges continued until the presiding judge, brow-beaten but, nontheless, truculent, adjourned the court. As the prisoner was escorted away, he saw a weapon on the Clerk's table. "I do not fear that," he remarked.
The next day, both the prosecution and the defendant, in their different ways, raised the stakes. Although contrary to the principles of English law, counsel for the prosecution stated that a refusal to answer the charges would be taken as an admission of guilt. In reply the Head of State widened the argument he had previously deployed. If he could be so treated, all citizens would be likewise at risk from the exercise of arbitrary power.
Overnight it was decided that the Head of State be given one more chance to answer the charges. But at the next day's sitting the result was the same and the court was adjourned once more. The Commissioners decided to call and examine witnesses but deferred until the next day consideration of exactly how this was to be done. In the end 30 witnesses were examined privately on 24 January.
Contrary to accepted legal procedure, the defendant was given no opportunity either to hear or to cross-examine people who testified again him.
By now the trial of the Head of State had got as far as it could with even a pretence of legality. The Commissioners proceeded to debate what sentence should be passed - whether removing the Head of State from office would be sufficient or whether the death sentence was required. Nonetheless a committee was formed to prepare a written draft of the sentence with a blank for the "manner of death".
The next sitting of the court, on 27 January, saw a repetition of the arguments of the previous sittings. The Head of State used his chance to speak before sentence was passed to maintain his assertion that the trial had no legal authority. Finally the judge blurted out the sentence: for engaging in treasons and crimes, for behaving as tyrant, traitor, murderer and public enemy "to the good people of this nation" - death.
This was the trial of Charles I. On 30 January 1649, the King was taken to the Banqueting House in Whitehall, designed and built during his reign, and which survives to this day with its ceiling painted by Rubens. The scaffold had been erected level with the first floor windows. When he stepped onto the planks, Charles gave his Garter insignia to Bishop Juxon, saying "remember". What did he mean by this injunction? Juxon took it as a reminder that he should give the medal to the King's heir, the future Charles II. I take it to mean - remember, this is judicial murder, the most heinous crime that states can commit.
I am indebted to two books: `The Trial of Charles I' by C V Wedgwood, published by Collins, 1964, and `The Last Days of Charles I' by Graham Edwards, published by Sutton Publishing, 1999, price pounds 19.99