The trial of Charles I was like putting a man on the moon. It changed everything. All the old views of divine right and kingship were thrown away. The world had now been turned 180 degrees upside down. Ideas about monarchy, government, Parliament - all of it would never be the same again. A new world was opening up.

On 20th January 1649, a High Court of Justice convened in Westminster Hall for the full trial of Charles Stuart. The trial was chaired by a little-known lawyer called Bradshaw who was the only person the Army could find willing to take on the charge. Charles' jury was 135 Parliamentary Commissioners.

The charge: that he 'had a wicked design totally to subvert the ancient and fundamental laws and liberties of this nation, and, in their place, to introduce an arbitrary and tyrannical government; and that...he hath prosecuted it with fire and sword, levied and maintained a cruel war in the land against Parliament and Kingdom, whereby the country hath been miserably wasted, the public treasure exhausted, trade decayed, thousands of people murdered, and infinite other mischiefs committed.'

How on earth could a King commit treason? By levying war against Parliament and the Kingdom of England, suggested the Court. The King was separate from the Kingdom, and Parliament now saw itself, not the King, as representing the will of the English people.

But for Charles, given that rex was lex, the King was law, the King was the embodiment of the nation and the very notion of the Parliament trying a monarch was absurd. Then there was the terrible sacrilege of prosecuting a King who ruled by divine right. It was a clash of ideas: of secular and religious, of monarchy and democracy. It was a clash of two opposing religious and social visions. And only one could win.

Charles's contempt for the Court was glorious yet hopeless. Seated on a dais in the middle of the floor, he was dressed majestically in a large black cloak embroidered ostentatiously with the emblem of the Order of the Garter. He refused to plead or remove his hat to signal any recognition of the Court's legality.

Charles rose to the challenge of the Court with all his majesty; his stammer seemed to fall away as he answered the charge of treason with contempt: 'Remember, I am your King - your lawful King - and what sins you bring upon your heads and the judgement of God upon this land, think well upon it.'

Again and again he returned to the issue of legitimacy - by what authority was he being tried? The King, he was told, was answerable to Parliament as 'the sovereign and highest court of justice..the sole maker of the law.' Charles answered that he could hardly be tried by a Parliament with no peers and only 56 MPs. 'I am your King', he pointed out, 'I have a trust committed to me by God, by old and lawful descent. I will not betray that trust to answer to a new unlawful authority.'

Debates about the legality of the court consumed the second and third days exasperating poor President Bradshaw. Time and again, Bradshaw asked Charles's response to the charge of treason and every time Charles disputed the authority of the Court. 'It is not my case alone, it is the freedom and the liberty of the people of England and... I must justly stand for their liberties', he protested to the Court. 'For if power, without law, may make law, may alter the fundamental laws of the kingdom - I do not know what subject he is in England can be assured of his life or anything he can call his own.'

Finally, Bradshaw's patience snapped. He ordered the clerk to read the charge and then removed Charles from the Court.