A king could be the guardian rather than the subverter of his subjects’ liberties. He was above faction, and could stand up for those who would otherwise be at the mercy of the rich, ambitious and often corrupt men who dominated parliament. This was how Charles I saw himself, and was why he declared, in his speech from the scaffold on January 30, 1649: “I am the Martyr of the People.”

But George III declined American pleas to behave like Charles I and defend them against acts of parliamentary oppression, by withholding royal assent to those acts. The Americans nevertheless decided to confer this power of veto on their president. Opponents who complained that “the foetus of monarchy” was being insinuated into the American Constitution were overruled. The elected monarch in the White House can reject acts of Congress. In Washington, legislative deadlock threatens to lead to the “constitutional death spiral” that in the 1640s produced the English Civil War.

It is not my purpose here to attempt a full account of what Nelson says. That would be impossible. Because his account is so contrary to the received wisdom that the American rebels were out and out democrats, it has to be fully buttressed by quotations from contemporary sources. But he sums up the new situation after the founding of the American republic with an epigram: “On one side of the Atlantic, there would be kings without monarchy; on the other, monarchy without kings.”

On this reading of history, the Americans preserve a more faithful version of “the ancient, equall, happy, well-poised and never-enough commended Constitution” of England than we do ourselves. At Westminster the monarch’s ability to avert legislative tyranny by refusing the royal assent had already been surrendered: Queen Anne was the last to use it, in 1707. Whig magnates had captured the Commons, made it the dominant institution and enriched themselves at public expense. So impressed are we by these grandees that we accept their claim to be on the side of freedom, and think this means they must have been democrats, or at least the glorious prophets of democracy. Their character as a corrupt and greedy oligarchy is treated as a minor and picturesque flaw. They can be forgiven almost anything because they stood, with the Tories, as a bulwark of liberty against the absolute Catholic monarchy of Louis XIV, towards which James II had attempted, from 1685-88, to steer us.

With the Act of Settlement of 1701, parliament ensured that we would have a Protestant monarchy. The main merit of George I, the Hanoverian princeling who ascended the throne in 1714, was that he was a Protestant, and could therefore be presumed to be a defender of our ancient liberties.

We have grown used to the idea that a representative has to be elected. A moment’s thought should be enough to correct this error. The monarch has a representative function which does not, usually, depend on election, but which does require widespread approval. As Jonathan Sumption pointed out, in a recent address on Magna Carta to the Friends of the British Library, medieval kings “could not govern without the tacit support of their subjects, and the active support of at least the most powerful of them . . . kings could not afford to act in a way that defied the contemporary consensus about how a king should behave.”