ISLANDS WERE SETTLED RELATIVELY LATE IN Human history. The inhabitants of the last of the planet’s habitable spaces to be colonised can be distinguished from mainlanders by philosophy rather than any of the physical or geographical characteristics by which one tribe separates itself from another.

As an islander-by-marriage myself – the maternal line of my husband’s family came from Mull, innermost and most fertile of the silver sisters of the Hebrides – I have first-hand experience of what it means to live, even with modern comforts, storm-bound for half the year and at the mercy of wind and weather for the rest.

Colonisation of islands, however fertile, was a last resort for a mainland population obliged, for one reason or another, to abandon their homeland and find sanctuary across the waters that separate one landmass from another. With them came their domestic animals and the wherewithal to plant their crops. Together the newcomers set about converting a ready-made landscape to suit their needs.

As a result, those who live on islands, however geographically divided, are as like to other islanders as Darwin’s Galapagos finches are to their brother finches on other Galapagos islands, and for much the same reason. Once possessed of the right-shaped beak – a problem for finches – or having adapted their needs to suit their surroundings – a problem for humans – man and bird found little reason for change. Islanders – avian and human – are conservative by nature. Palaeontologists scraping around in prehistoric middens find domestic implements still in use on islands to this day.

My husband Nicholas knew and loved the Western Isles from childhood, and I too learned over the years to love their windswept beauty. When our children were grown and gone and there was reason to find a place where he could write without distraction, the island became our home. As far as our crofting neighbours were concerned, it was enough that the family kilt, a length of mud-brown homespun, had seen distinguished service in support of Bonnie Prince Charlie at the Battle of Culloden in 1746. The loss of independence that followed defeat by the English armies is nowhere felt more keenly than on the islands.

Thirty years ago, the islanders – a crofting community whose activities as farmers, shepherds and fishermen depended on the season – supplemented self-sufficiency with summer services to tourists. For the rest of the year, the island way of life was more or less as it always had been: hard-working, neighbourly and frugal. The original settlers were dark-haired Celts, short of stature and fierce of disposition, who intermarried, to put it politely, with the tall, blond, blue-eyed Vikings who dropped anchor in the sheltered coves to re-victual their longships by raiding the island’s cattle. The cattle were not, as might be expected, the shaggy-haired, wide-horned, semi-feral brown highland cattle of the Scottish mainland, but small, black-coated, short-haired dairy herds introduced from Ireland by the monks who settled Mull’s smaller sister, the sacred island of Iona.

To this day, the descendants of those hardy souls whose livelihood depended on the rocky outcrops littered throughout the world’s oceans share far more than sets them apart. Those things that islanders share with other islanders – philosophical rather than physical – include long memories, traditions preserved through singing and storytelling, wariness of strangers, care for widows and orphans, an egalitarian way of life and a willingness to do whatever it takes to survive.

Island-dwellers have good reason to distrust strangers. Even if seemingly they come in peace, there’s no guarantee that these same strangers won’t run off with your wife, your cattle and the contents of your store cupboard. Some defend their own by retiring inland, some hold fast to their territory, some greet newcomers with open arms in the hope they’ll do no harm. Whatever the choice, island existence is fragile, good reason to look after your own.