It is one of the most remote inhabited islands in the world, more than 1,200 miles off the coast of Africa. It is one of the earliest British colonies, recognised and formally chartered to the East India Company in the brief administration of Oliver Cromwell’s son. It boasts more unique endemic species than any other patch of land on the planet. And it is, famously, a place of exile and imprisonment, the island prison for the final six years of an ex-emperor’s life. St Helena is forever associated with Napoleon.

It is also, oddly enough, associated with many other famous people: the Duke of Wellington, who ironically on an earlier stay had slept in the very same house in which Napoleon was billeted on the night that he disembarked; Charles Darwin, who passed through in 1876 and presciently noticed the extraordinary wind turbulence on the very clifftop where the expensive new airport was unfortunately sited some 140 years later; Edmund Halley, the astronomer royal whose pioneering visit in 1676 and construction of an observatory led to his recording the transit of Mercury and other important astronomical discoveries; Captain Cook on several of his many voyages; and the notorious Captain Bligh, who arrived in 1792 with yet another cargo of breadfruit in transit from Tahiti to the West Indies – the very plants that three years earlier had triggered the famous mutiny on the Bounty.

Any biography of the island must also look at the extraordinary role that it played, during the long rule of the East India Company, in Britain’s trade with the East, when St Helena became a vital staging post for ships sailing round the Cape of Good Hope on their return journey from India. Hundreds of ships used to call in every year, but. with the opening of the Suez canal. hardly any merchant vessels needed to stop over, and St Helena began a long decline into penury and obscurity.

A biography must also look at the people – never more than a few thousand – who came from all parts of the world, so that today’s islanders are descended from British sailors and adventurers, slaves from Madagascar, indentured Chinese labourers and Boer prisoners of war billeted on the island for almost three years at the turn of the last century.

Arthur MacGregor has succeeded masterfully in pulling together all these disparate facts and elements of St Helena’s history. His account of the people, environment, ecology, governance, scientific investigations, communications with the outside world and, of course, the six-year stay on St Helena of Napoleon and his large entourage, together with some 2,000 British troops stationed to guard him, explains why St Helena has played such a prominent role in world affairs, despite its small size and isolation, and why it evokes such fascination for those who visit.

MacGregor’s book is scholarly. He references most of his statements and anecdotes with footnotes. These are often helpful and contain nuggets of information that are piquant and relevant: it is amazing to learn, for instance, that during the Atlantic patrols between 1840 and 1867 the Royal Navy’s West Africa Squadron apprehended and brought to the island four hundred and twenty-five slave ships that had transported between 21,500 and 25,000 enslaved men, women and children. The slave traders, mostly Portuguese, were tried at the vice-admiralty court. The slaves, many of them dead by the time the ships were brought in to St Helena, were ether buried in mass graves or consigned to quarantine on a remote part of the island until they were well enough to be sent on to the West Indies as indentured – but free – labour. St Helena, which contains the largest slave grave in the world, is honouring with a new memorial the bones of the three hundred or so skeletons of enslaved people excavated during the building of the access road to the new airport.

The book is informed by extensive reading, and numerous old sources are quoted at length. The island’s natural history is presented in meticulous detail; so also is its historic role as a prison fortress, and the many attempts by various governors to get this or that farming project or local industry going to offset the island’s chronic budget deficit. Few ever paid off; most fell by the wayside from sudden changes of policy or governance, from apathy or because some crackpot initiatives were never going to work.

A huge amount of detail is compressed into only 205 pages of text. For those who know the island, MacGregor’s well-illustrated handbook provides a succinct account of one of the world’s loneliest and most mysterious places.