I say St Helena, you say Napoleon, or possibly vice versa. It’s undoubtedly the case that this tiny and remote island is most famous because of its reluctant and ex-imperial guest between 1815 and his death in 1821. Large numbers of books have been written about Buonaparte’s time on the island, from reminiscences by people (included a young girl, Betsy Balcombe) who were there, to later speculations on the cause of his death: poisoning by arsenic in the wallpaper got a mention, I seem to remember.

The exiled Napoleon gazes in the general direction of France. Longwood House, where he lived, is today French property.

However, the island, granted to the East India Company by Oliver Cromwell in 1657, first settled in 1659, and now with a population of about 4,250, has a much longer history as a crucible of environmental studies – and as an awful warning of the fragility of an isolated environment exposed (usually by human activity) to alien invasion. Alfred Russel Wallace wrote on the extraordinary and unique ecology of islands, and the Victorians were of course aware of the problem of extinction of species through human intervention: consider the dodo, and the great auk.

St Helena was first discovered (uninhabited) by the Portuguese in 1502. Situated in the south Atlantic (at 15° 57′ 0″ S, 5° 43′ 0″ W), it is one of the remotest islands in the world: so much so that it is possible that the navigator Joao da Nova actually discovered Tristan da Cunha (a mere 1,510 miles further south), and that St Helena was not in fact lit upon until July 1503 by Estevao da Gama, cousin of the more famous Vasco.

One of the earliest descriptions of the island is given by Jan Huyghen van Linschoten in his 1596 account of his voyage to the East Indies.

Linschoten: a colour version of the frontispiece of his book, with St Helena bottom right.

The island has strategic significance for Portuguese fleets, in that on the return journey, ships can at first make their way separately (smallest and slowest first) as they are in no danger of attack by ‘Rovers’, but they rendezvous at St Helena and proceed up the Atlantic in convoy. When Linschoten’s comrades sighted the island, ‘there was so great joy in the ship as if we had bene in heaven’, and they found five ships which had set out before them anchored in the harbour.

Linschoten describes a landscape of high hills, ‘so that it commonly reaches unto the clouds’, but ‘verie ashie and drie’, clothed in abundant trees which were of no use for timber except to burn, ‘for it hath no special substance, but sheweth as if it were halfe consumed … When the Portingales first discovered it, there was not any beasts, nor fruite, … but a great store of fresh water, which is excellent good, and falleth down from the mountaines … the Portingales fill their vessels with fresh water and wash their clothes’.

Map of St Helena by the Dutch cartographer Pieter van der Aa (1659–1733).

That’s the good news: the bad news for the future of the island’s unique environment is that ‘the Portingales have by little and little brought many beastes into it, and in the valleyes planted all sorts of fruites: which have growne there in so great abundance that it is almost incredible. For it is so full of Goates, Buckes, wild Hogges, Hennes, Partridges, and Doves, by thousands, so that any man that will, may hunt and take them … Now for fruites, as Portingall Figges, Pomgranets, Oranges, Lemons, Citrons, and such like fruites, there are so many, that growe without planting or setting, that all the valleyes are full of them, which is a great pleasure to beholde, for that it seemeth to bee and earthly Paradise.’

Especially a Paradise, one imagines, for men who had been many weeks or months at sea, living on salt meat and brackish water: indeed, sick crewmen were left on the island to recover, with supplies of ‘Rice, Bicket, Oyle, and some Spices’, everything else being readily available. The king of Portugal specifically forbade anyone to settle there, ‘because they should not destroye & spoyle the countrie’. A so-called ‘hermit’ who was allegedly doing penance there was found to be killing and skinning up to 500 of the goats and bucks a year, and selling the leather: he was taken back to Portugal. Some escaped African slaves hid on the island and built up a community of about 20 people, but again they were hunted down and expelled.

The said ‘Goates, Buckes, wild Hogges’ and so on wreaked havoc on the native flora, but worse was to follow. English and Dutch ships, having located the island, used it as a base from which to attack the Portuguese fleets, which began instead to skirt up the coast of West Africa (where they were building forts as bases for the Atlantic slave trade) instead. But the East India Company’s plan from 1657 onwards was to settle the island permanently with planters.

The fort at Elmina, Ghana, built by the Portuguese. (Credit: Jenny Pate)

The project almost came completely to grief: a cycle of deforestation leading to soil erosion and drought (to say nothing of rats, brought in ships and with no natural predators) caused the then governor in 1715 to suggest that the population be transferred to Mauritius, but the island was so important to the EIC that it subsidised the growing community, which by 1723 consisted of 1,110 people (including 610 slaves). Successive governors in the eighteenth century tried to restore the forests (and eliminate corruption and control the consumption of alcohol …).

St Helena in the 1790s. Note the denuded hillsides.

As a site of scientific interest, St Helena, like Ascension, was important in the development of astronomy. Edmond Halley (of comet fame) visited in 1676, while he was acting as Flamsteed’s assistant at the Greenwich Observatory: his job was to set up an observatory to map the stars of the southern sky. While there, he saw a transit of Mercury, which convinced him that Jeremiah Horrox was right, and that observing a transit of Venus would enable calculations about the extent of the universe. Almost one hundred years later, a voyage was undertaken, and the rest is history in all sorts of scientific fields: Cook in fact called at St Helena for water and supplies on the way home from the first and second voyages.

A view in St Helena, by the traveller and Egyptologist Henry Salt (1809).

Napoleon was the first, but not the only, political detainee on St Helena. Dinuzulu, son of Cetshwayo, king of the Zulus, was exiled there for seven years from 1890 after opposing the annexation of further Zulu territory by the British, and 5,000 Boer prisoners were dumped there during the Second Boer War. The population was probably at its height during Napoleon’s enforced stay, when there were over 6,000 people (not including ships’ crews temporarily in the port), and again in 1901, because of the Boer prisoners. In the 1840s, when the Royal Navy used it as a station in the anti-slavery drive, over 15,000 ‘Liberated Africans’ passed through.

All of this degraded the original environment beyond recognition. Introduced land mammals, and the use of trees for fuel, caused the extinction of much of the endemic flora, and hunting (and feral cats, originally introduced to deal with the rats …) reduced the population of native birds, though the island remains important in the migratory cycle of south Atlantic seabirds. The St Helena plover, the island’s national bird, has ‘Critically endangered’ status on the IUCN list, and a depressing number of unique birds – the St Helena petrel, shearwater, crake, swamphen, dove, cuckoo and hoopoe, and Olson’s petrel – are now extinct. Others, such as Audubon’s shearwater, the white-faced storm-petrel, and the red-footed booby, are extirpated, i.e. no longer exist on the island, though they are found elsewhere.

Charadrius sanctaehelenae, the wirebird or St Helena plover, now critically endangered.

The red-footed booby, thriving in the Philippines (cf. its cousin, the blue-footed booby).

Similarly with the endemic plants: the St Helena heliotrope (recorded once, in 1808), dwarf ebony, and olive no longer exist (the last wild plant of the latter having died in 1994, and the last in cultivation in 2003), while the St Helena boxwood is critically endangered.

The St Helena olive, Nesiota elliptica.

The St Helena ebony (so called because its black wood was used as inlay in craft items) clings on, literally:  two wild species were discovered clinging to a cliff. These have been propagated from, and there are plants in botanic gardens all over the world. There is one in Cambridge, but it has been looking increasingly unsprightly over the last few weeks. The ‘St Helena’ bed in the temperate greenhouse is being made over, so hopefully some younger plants will soon replace it.

The St Helena ebony, Trochetiopsis ebenus, looking a bit tired.

Leaves on the bush.

Charles Darwin was on the island in July 1836, on the homeward voyage of the Beagle. He wrote, presciently: ‘there is reason to believe that the naturalised plants and animals have nearly or quite exterminated many native productions’. Indeed there is.

Caroline