Watching a coronation is the constitutional equivalent of visiting a zoo, and finding a Triceratops in one of the enclosures. Charles III sits on the throne of the United Kingdom by virtue of his descent from two fabulously venerable lines of kings. The house of Wessex, which fashioned the united kingdom of England back in the 900s, traced its origins to the early 6th century; Cináed mac Ailpín, or Kenneth I, traditionally ranked as the first king of Scotland, stood in a line of succession to the no less ancient monarchy of the Picts. Countries that can boast a head of state based on criteria reaching back to such a distant age are vanishingly rare. Only Japan and the Vatican can really claim to outrank Britain in such stakes. Even they cannot rival the sheer antiquity of the ritual that will be staged in Westminster Abbey on Saturday. The United Kingdom is alone in Europe in marking the accession of a new monarch with a coronation. Key elements of the ceremony – that it should be presided over by the archbishop of Canterbury, that two bishops should escort the king, that the congregation at the end of the service should join in acclaiming the newly crowned monarch – date back to the coronation in 973 of Edgar, the great-grandson of Alfred the Great. Dunstan, the formidable archbishop who composed the order of service, had in turn drawn on even older exemplars: some native to Britain, others reaching back to Roman times. Oldest of all, however, and most imbued with a sense of the sacred, was one ritual in particular: an anointing. The inspiration for this, older than England, older than the house of Wessex, older than Christianity itself, was to be found in the Old Testament: “Zadok the priest and Nathan the prophet anointed Solomon king.” This same verse, chanted at Edgar’s coronation and famously put to music by Handel, will be sung as well during Saturday’s service. Charles III will share in a ritual that originally marked out the kings of Israel – Saul and David and Solomon – as the adopted ones of God. The 21st century will be joined by means of a living ceremony to the bronze age. How will this play out among the subjects of the new king? The British are an immeasurably more secular people than they were when the last coronation was staged 70 years ago. Almost 40% of the population of England and Wales described themselves in the most recent census as belonging to “no religion”. Meanwhile, the Churches of England and Scotland, both of which the monarch is constitutionally pledged to defend, are in decline relative both to various other Christian denominations and to religions that had barely registered in Britain when Queen Elizabeth II came to the throne. There are many in the country who are not just hostile to Christianity but wholly ignorant of its history, its doctrines, its ceremonies. That its head of state rules by virtue of claims that are rooted not merely in the supernatural, but in a specifically Christian understanding of the supernatural, is an aspect of the constitution that often remains discreetly veiled. There will be no hiding it, though, at the coronation. The insistence of Charles III on following the example of his mother, and refusing to allow his anointing to be screened on TV, will serve only to heighten viewers’ sense of the sacral quality of the ritual. A British coronation stands in a line of descent from the age of Solomon or it is nothing. Most people watching the service next weekend probably will not care very much. A spectacle is a spectacle, after all, no matter its theological underpinnings. Yet it is likely that a substantial minority of people in Britain, rather than being dazzled by the display in Westminster Abbey, will find their distaste both for the monarchy itself and for its supernatural pretensions only confirmed by the pomp and ritual of the coronation. Catherine Bennett, writing in this paper recently, despaired of how arguments for a secular coronation “appear to have dented neither the church’s coronation ambitions nor the palace’s matching enthusiasm for spiritual choreography and knick-knacks”. It is not hard to imagine the spectacle of a ritual with its roots in the bronze age confirming for many people – republicans, secularists, atheists – a conviction that Britain needs to be brought properly into the 21st century. Such has been the speed of social, cultural and moral change over the past few decades that the role traditionally played by the monarchy as a living symbol of the country’s past, rather than playing to its advantage, as it has always tended to do, might instead begin to leech it of legitimacy. Rituals that people no longer believe in can easily come to seem problematic as well as ridiculous. Equally, however, the reminder that the coronation will give to people in Britain is that its roots are fabulously ancient, that its constitutional structure is suffused by notions of the supernatural, that it is altogether a much weirder country than it might on the surface appear, may serve to thrill as well as appal. It was evident, during the period of mourning for the queen, that many were surprised by how moved they felt, and how eager for ritual. There are spiritual currents that still run deep in Britain, even if they are as likely to be expressed by the laying of a Paddington Bear toy before a makeshift shrine as by the lighting of a candle in a church. The perfect symbol for these currents was provided by the Green Man that featured on the invitation to the coronation: a figure that can be interpreted simultaneously as Christian and pagan, and adorns both medieval churches and the placards of Extinction Rebellion. The king – who as prince greeted the new millennium by going on Thought for the Day and praying for a rediscovery of “a sense of the sacred in all that surrounds us” – is, perhaps, less out of tune with the vibes of the age than he might appear. There may be magic in monarchy yet. Tom Holland is a journalist and author