We can thank reindeer for our being here. It was the northward movement of their herds that led the first permanent settlers to come across the land-bridge from France to Britain at the end of the Ice Age, 11,500 years ago. After the land bridge was flooded about 8,200 years ago, our numbers were reinforced by seaborne migrations from the continent: Neolithic farmers from about 6,300 BC; ‘Beaker People’ with their Bronze Age technology about 4,000 years ago; Iron Age Halstatt culture Gauls about 450 BC; and the fierce Belgae just prior to the arrival of the Romans.

Gaels from Ireland (with their own strong dose of Gaulish blood), called ‘Scots’, flooded into western Scotland towards the end of the Roman period, overlaying the indigenous Picts. As Roman rule crumbled, Saxon mercenaries in England encouraged their Germanic kin to share in the spoils, and many Romano-Britons fled to Armorica, that became known as Brittany. Then, just as things were quietening down, Vikings started ravaging our shores in the 9th and 10th centuries AD, and their kinsmen, who had settled and been civilised in Normandy, took over England in 1066. They conquered Wales and Ireland soon after and also settled, with or without the permission of the Scots kings, in Lowland Scotland.

Jews, whose presence in our cities may have gone back at least to Saxon times, were expelled by Edward I in 1290. In the opposite direction came Flemish weavers, who swelled the population of Norwich and parts of London during the Middle Ages.

By the Middle Ages, all this migration into Britain had produced a mongrel race, whose local identities were forged by a common interaction with the landscape and seas around us. Then, in 1584, Walter Raleigh, a shining product of the mongrel rag-bag that had become ‘Merrie Englande’, set sail to found the first English colony in the Americas, that was named Virginia, after Elizabeth I, the ‘virgin queen’.

His efforts failed, but under Elizabeth’s successor James I, a permanent settlement, Jamestown, was established in Virginia. Early colonisation focussed on the coast from Maine down to what became South Carolina, and Bermuda, which lies far off the South Carolina coast. The American colonists were a real mixture. There were sons of gentry and aristocratic families, like the Gorges, Pelhams and Wests, Lords De La Warr (hence the American place name Delaware). Some had lines of descent going back to royalty, as do their millions of American descendants, including most of the Presidents. But on the ships to America there were also plenty of merchants, servants and tenants, being carried there to cultivate the land, and no small number of prisoners, especially those on the losing side of the Civil War and the 1685 Monmouth Rebellion. Of course many people of all classes also went to escape religious persecution – Puritans in the early 17th century, Catholics in the 1630s and in Cromwell’s time, more Protestants thereafter.

James I’s accession to the English throne started a steady migration of Scots down what Dr Johnson once described bluffly as ‘the most noble prospect a Scotsman has ever seen’ – the road south into England. It is said, though seldom proved, that the Scots Covenanting armies that came south during the Civil War resulted in Scots soldiers marrying and settling down in England. Other Scots went further: merchant burghers settled in the Nordic and Germanic lands with which they traded: great numbers of Dutch people, for example, have Scottish forebears. Sons of merchants and landed proprietors became officers in the armies of France, Germany, Scandinavia and, particularly, Russia.

Better documented influxes came from the Continent. Walloons were Flemish Protestants who came to England to escape Catholic persecution in the 16th century. They were followed after the St Bartholomew’s Day Massacre of 1572 and especially after the Revocation of the Edict of Nantes in 1685 by many French Protestants – the Huguenots – crossing the Channel for the same reason. These asylum-seekers were generally welcomed, for they were mostly hard-working tradesmen, merchants or moneyed nobles who became valued tax-payers; their skill in silk-weaving was particularly prized. They were encouraged to settle in Canterbury, Southampton, Norwich and Bristol plus Spitalfields and Bethnal Green in London. Later immigrants from Europe included small numbers of Greeks, many Jews, and Italians, who came in significant numbers in the late 19th century, fleeing poverty at home: significant numbers settled in Glasgow and Edinburgh, specialising in selling fish and chips and ice cream – the ancestors of the likes of Armando Iannucci, Peter Capaldi and Tom Conti.

While this was going on, Britons were questing ever further abroad. The American revolution of 1776 ended the old practice of transporting criminals to the Americas, so in 1787 the First Fleet of convict transport ships set sail for Australia, establishing the first penal colony there. Colonies spread, and in the mid-19th century gold was discovered, triggering a massive influx of eager, free British migrants to Australia. Canada was being colonised from the 1670s, more so after General Wolfe’s capture of Quebec from the French in 1759 and particularly after our loss of the American colonies. Meanwhile, Britain annexed the Cape of Good Hope from the Dutch in 1795 leading, in the mid-19th century, to substantial British migration to southern Africa as well. Always, migrants covered the whole social spectrum: land-hungry nobles, eager missionaries, aspiring farmers, desperate criminals and boatloads of unwanted orphans and other poor children.

In the late 18th and early 19th century, Highland Scottish landowners discovered that vastly more money could be made by grazing sheep on their land than by collecting rents from their tenant farmers. Vast swathes of the Highlands were ‘cleared’ and the dispossessed farmers were forced either to live in miserable crofts on liminal land where even the sheep couldn’t graze, or to leave: many left through choice. Canada was the destination of many, or America. Here they found the vast numbers of Irish people who had gone thence, fleeing the potato famines. In South America, Irish Catholics flocked to Catholic Argentina, where they still constitute a substantial community, rubbing shoulders in Patagonia with colonies of Welsh miners, who remain a distinct community there to this very day.

As far back as records allow most of us to trace family lines, about 1600, the general trend (with the exception of the Irish) has been of relatively small-scale migrations inward, and pretty large-scale migrations, caused by a hunger for new land, outwards. Thus, we all have copious relatives, traced or not, all over the English-speaking world, and no small number beyond. Few of us can trace very far back without finding a healthy dose of foreign blood – that makes our ancestries, like our island story, so much the richer.

Timeline: Migration