At the edge of the world: Postcode helps bring remote colony into the modern age

They are the most remote islands on the globe, but the British colony of Tristan Da Cunha has finally joined the modern age

Put on the map by Portuguese explorers; used as a stopping point by Americans at the height of the whaling boom; and finally settled as Britain sought to monitor the exiled Napoleon; the world's most remote islands had entered the age of online shopping with the help of a UK postcode.

The windswept archipelago, a tiny British protectorate, is a week's voyage across the south Atlantic from Cape Town. Once you reach its rocky shore there's no natural harbour.

Mr Hentley's book had to be lowered down a rope ladder and on to one of the barges that regularly battle 100mph winds to bring supplies. Often ships are forced to turn back to South Africa after a week of waiting for the weather to calm enough to send a launch.

Appropriately for such a self-reliant community, the first internet purchase was a history of Tristan, written by a local, but that belied the importance of the purchase. "This will open up new horizons to the Tristanians," Mr Hentley, the island's administrator, told The Independent by satellite phone from the only permanent settlement, the grandly named Edinburgh of the Seven Seas. "Without the postcode we couldn't get online companies to deliver."

Rising out of the spray of the South Seas, the group of five volcanic rocks are a definition of isolation. Despite their outstanding natural beauty and extraordinary birdlife, including the Rockhopper penguin and a massive community of albatross that has made them a World Heritage Site they are visited by only a handful of ships each year. To most they remain a cluster dots on the map, halfway between Cape Town and Montevideo.

The climate is less than tempting. According to its own website Tristan offers "driving wind and rain in all seasons". The next landfall in the archipelago after Tristan is Inaccessible Island. The namers might have been trying to put people off.

Aside from the deep sea trawlers that provide whatever the archipelago's hardy subsistence farmers and lobster fishermen can't grow themselves, the only visitors are infrequent cruise ship passengers. It is 1,450 miles to the next human settlement of St Helena, itself a place made famous for bleak exile.

For the most isolated community on earth, the arrival of outside ships brings anxiety and novelty in equal measure, Daniel and Karen Schreier revealed in their recent book, Tristan da Cunha.

While many of the 286 Tristanians are proud of the hospitality of their community and guide visitors through its spectacular scenery and wildlife, for others outsiders are a cue to shut themselves up indoors and stay there until the visiting ship weighs anchor. And tourists can bring uncomfortable side-effects to a settlement unexposed to modern disease. In 2000 they left behind a whooping cough epidemic that tortured many inhabitants for months afterwards.

The islands take their name from Tristao Da Cunha, who was first to set eyes on the so-called "mountain of the sea" in 1506. The Portugese admiral is thought to have been dissuaded from attempting a landing on the island by its intimidating appearance. Visible from up to 100 miles away, its sheer black cliffs climb out of the rough sea and through the cloud line to a snow-capped mountain peak. After thinking better of a shore trip, the Portugese put it on the map and generously gave it his own name.

By the 17th century Tristan had found itself on the maritime motorway as trade winds blew merchant ships down the coast of Brazil and then out into the open seas before attempting to round the Cape of Good Hope. But it was the whaling boom a century later that pushed people to set foot on the barren volcano.

The American captain John Patten, from Philadelphia was the first to set up base there. His compatriot, Jonathon Lambert, was to follow in Capt Patten's footsteps in 1810 as he attempted to build a trading station and rename the archipelago - the Refreshment Islands. Lambert soon realised the venture was doomed and dispatched a begging letter to the Crown asking for rescue.

There was still no official answer three years later when the HMS Sieramis arrived to find the Italian Tomasso Corri was the only living soul on Tristan. He was suspected of murdering his business partners over a lost treasure.

It was the admiralty's fears that Napolean's exile on the not-so-nearby St Helena would prove as short-lived as his exile on Elba that finally ushered Tristan into the British empire. HMS Falmouth took possession of the islands on behalf of George III in the August of 1816, setting up Fort Malcolm.

Yet again, however, Tristan would get the better of its new intruders. The rugged rocks underlined their nickname as the "Graveyard of the South Atlantic" as HMS Julia went down off the fort with all hands and the garrison packed up and left. Only three men, a non-commissioned officer and two soldiers asked if they could stay on.

Among them was William Glass, with his South African wife and two children. The Scottish corporal, whose descendants continue to live on the islands today, has a fair claim to rival Karl Marx as a communist visionary. It was Glass who drafted the island's constitution in 1817, stipulating among other things that: "The stock and stores of every description ... shall be considered as belonging equally to each". And, "that in order to ensure the harmony of the Firm no member shall assume any superiority whatsoever, but all to be considered as equal in every respect."

The first written account of life among the egalitarians came seven years later when the renowned painter and naturalist Augustus Earle was stranded on Tristan after his ship left without him. The castaway artist's diary of the ensuing nine-month stay paints a harsh but happy picture of island life.

He writes of a "Scotchman" who behaves with "every possible kindness" and an abundance of children. He writes fondly of a young sailor, called White, who along with a servant girl called Peggy "are the second couple to be married on the island, and no two people can be happier".

The descendants of the egalitarian Scot and the lovestruck sailor are still there today. The entire population are the direct descendants of just seven families.

The only disruption to Tristan's human history came in the 1960s when the long dormant volcano awoke with terrifying consequences, burying Edinburgh in ash and forcing a two-year retreat to Cape Town. But the Tristanians returned.

As Mr Hentley - a career diplomat whose previous postings were Seoul and Nigeria - explains, Tristan boasts more than averagely close-knit community. "It's like stepping back in time. On the surface it has the television, through British services broadcasting on the Falkland Islands, and shops with products from Cape Town, but underneath it is different. It's more like the remembered 1950s with that post-war sense of community spirit."

The community remains distrustful of hasty outsiders and wary of comparison to its fellow British outpost Pitcairn, which was rent last year by a multiple child abuse trial.

For those hardy few who stay long enough to win friends there is a special name, "station fellas". It's part of an entire local dialect some of the highlights of which include "Hatcha" - an exclamation to frighten children. No one can remember its origin. The explanation for the existence of at least eight different words for potato is easier: it is the island's main crop.

Crime is not a problem. "You never lock your house here. You're more likely to find someone breaking in to leave something behind - like fish if there's been a good catch," Mr Hentley said.

As the locals make their way from the Prince Phillip community hall to the Albatross Inn much as they have for decades, the main challenge ahead would, however, sound familiar to their distant European cousins. Mr Hentley faces the uncomfortable task of telling the Tristanians that they are going to have to work longer in one of the world's least hospitable climates.

"The population is greying," he said. "We've got one woman who is 99; we are hoping she'll make it to the centenary next year."