When, last summer, a group of Orcadians declared they’d like to leave the UK and join Norway, it became clear just how little most of us in the south understand Orkney. Friends who know I go there often ask me where it is (somewhere near the Hebrides?), how many Orkney islands there are, and whether they are mountainous or flat.

As Peter Marshall explains at the start of this astonishing tour de force, the 70-odd Orkney islands lie just 25 miles north of Scotland, separated from the mainland by the Pentland Firth – the point, he says, at which ‘the North Sea meets the Atlantic, a place of hidden, treacherous whirlpools, and one of the world’s most powerful tidal currents’. A short, turbulent crossing carries the traveller from the rough terrain of Sutherland into a fertile, Gerard Manley Hopkins-like landscape, ‘plotted and pieced – fold, fallow and plough’, islands patchworked with fields, often running right down to the sea. The landscape is fluent, not mountainous, and with no trees to interrupt the view, Orkney is, as Marshall perfectly describes it, ‘domed by the sky and belted by the sea’.

Black Patie ruled with ‘coercion, cruelty and tyranny’, and built himself a magnificent Renaissance palace

And, though the population is only just more than 20,000 (less than half that of Windsor), Orcadians are high achievers. ‘Eggs and professors’ were said to be the islands’ main exports in Victorian Britain (Kirkwall boasts the oldest public library in Scotland), and in the 20th century Orkney produced two world-class poets: Edwin Muir and George Mackay Brown.

Why the pull to the north? The earldom of Orkney was governed by Norway until it was given in lieu of a wedding dowry to James III of Scotland in 1468. If that seems a long time ago, in terms of islands continuously inhabited for at least 8,500 years, the intervening centuries are just the blink of an eye.

Marshall, the winner of the 2018 Wolfson History Prize for his book about the Reformation, was born and grew up in Orkney, his family originally from the island of Sanday, perhaps best known in recent years as the final home of Sir Peter Maxwell Davies. He is confident – and rightly so – that Orkney is a ‘most bookworthy place’. But rather than homing in on the parts of the islands’ history for which most Orcadians harbour a romantic reverence – the arrival of the Vikings in the eighth century, or the central role played by Scapa Flow in the two world wars – he has chosen to shine a light on three centuries much less often explored. They are bookended by the visit of James V at midsummer in 1540, and Sir Walter Scott’s arrival in 1814 on the lighthouse yacht Pharos.

These were centuries of tumultuous religious, political and economic upheaval that saw the forging of Scotland, then Britain, through a rollercoaster of revolution, civil war, the Commonwealth, the Restoration, the Glorious Revolution, unification and rebellion. If it seems surprising that a tiny number of out-of-the-way people were players in such momentous events, Marshall makes the obvious but important point that ‘by virtue of participation in trade and proximity to sea lanes, islanders often enjoy greater contact with the outside world than inhabitants of inland regions’.

I had always vaguely imagined that, after Orkney’s patron saint Magnus allowed himself to be martyred by axe stroke on the island of Egilsay on Easter Monday 1117, hoping to bring peace to the islands, Orkney had dreamed its way through the next few centuries in a calm, pastoral idyll. What is surprising about Storm’s Edge is that it portrays a people not only bowed down by the endless, arduous cycle of the agricultural year, but in a state of almost constant strife – never more so than under the rule of the ‘Black Patie’, the ‘ruthless, unscrupulous, ambitious, spendthrift, grasping and vainglorious’ Patrick Stewart. He was the earl who ruled Orkney with ‘coercion, cruelty and tyranny’ in the late 16th and early 17th century, and built himself a magnificent Renaissance palace. The  massive remains of it still stand in Kirkwall, next to St Magnus Cathedral, ‘the Light in the North’.

‘Orcadians are great lovers of war,’ wrote the 18th-century Orkney historian George Eunson. As well as battles fought on Orkney soil – in 1529, a Scots army sent to quell rebellious Orcadians was roundly trounced near Summerdale – Marshall gives us vivid glimpses of ordinary Orkneymen playing their parts at moments of high historical drama. On HMS Bellerophon, which conveyed him to England prior to his final voyage into exile on St Helena, Napoleon was cheered by the friendship of an Orkney sailor, James Tait. At least one Orcadian, William Mainland from Rousay, served as an able seaman at Trafalgar on Nelson’s flagship Victory. And tradition has it that an Orkneyman called Cooper helped carry the dying Nelson below decks.

Through such involvement in history, ‘the place beyond’ gradually became ‘the place just within’. ‘We are all Britons,’ declared a Sussex clergyman, John Lettice, in 1794, ‘from the Land’s End to the Orkneys.’ But Marshall is keen to ‘make the periphery central’, to show that, for those who lived there, Orkney remained the still point of the turning world: its own small, green universe. So at the same time as writing about great national and international events, for which he deploys a staggeringly large dramatis personae, he deftly weaves in vignettes of a life that remained unique to Orcadians: women singing at their querns, ‘the sweetness of their voices softening the harsh grate of stone on stone’; men luring vessels to grief on the rocks ‘so that they get a supply of material for fire from the wrecked ships’.

Walter Scott was taken to meet Bessie Millie, in the business of selling favourable winds to sailors

There is often little distinction between the ordinary and the fabulous. Magic and religion were parts of a common system, many Orcadians pursuing ‘ingrained habits of pilgrimage to old kirks and chapels’ long after the Protestant Reformation had supposedly stamped out Catholicism – just as Orkney Norn, a form of Old Norse, carried on being spoken by ordinary people long after it had ceased to be the language of government.

Witchcraft, if not an ‘everyday occurrence’ was an ‘everyday possibility’. Marshall was moved to write this book because he has a Sanday ancestor, Marion Paulson, who was murdered by a witch, Annie Tailzeour, in 1624. Between 1563 and 1738, witchcraft was a capital crime and, having been tried in St Magnus Cathedral, witches were fastened to a stake, strangled and burned. Relative to the population, around twice as many witchcraft accusations were levelled in Orkney as in Scotland overall. Yet generally witches were what the Orcadians call ‘cheust folk’ – just people – whose crimes very often looked like simple good deeds. ‘Only the toss of a sixpence separated the healer from the curser, the wise woman from the witch.’

Orkney’s reputation as a haunt of witches was still robust in the early decades of the 19th century when Scott stepped ashore, and in Stromness he was taken to meet Bessie Millie, an old crone in the business of selling favourable winds to sailors. In part, she provided the inspiration for his novel The Pirate, which in turn put Orkney on the map for Victorian tourists. Since then, the popularity of the islands has grown. As Marshall mentions in his penultimate paragraph: ‘Orkney, in the 21st century, regularly takes the top spot in social surveys of the “best place to live” in Scotland, and sometimes Britain, too.’ We mustn’t lose her to Norway.