A 10ft bronze statue, depicting a family of four leaving their Highland home stands in the Sutherland village of Helmsdale; its twin in the Canadian city of Winnipeg.

The title of the former is Emigrants, the latter Exiles. This remarkable book by Professor James (Jim) Hunter could be said to be the story of these two sculptures. But it is so much more.

It is in itself a memorial to the thousands Gaels who fought to stay, but in the end had to quit that northern county because of the policies pursued by the aristocratic house that shares the name.

Scotland has long associated the first Duke and Duchess of Sutherland with the Highland Clearances or “improvement”. It is ironic perhaps that they didn’t actually have these titles until 1833, by which time their lands had been well and truly “improved into a desert”, as Cromarty’s polymath Hugh Miller described it.

In this book, they are still the Marquis and Marchioness of Stafford. They had people removed from land that had supported human settlement for millennia. They had to make way for large sheep farms. That much of clearance is well rehearsed. But the human mechanics of the process have never been better examined.

The Staffords believed they were making a district which hitherto had done little for Britain’s economic growth, into a significant contributor. But they didn’t want the people to leave the county. They were to have a new life with crofts on the coast where they could fish or pursue a non-agricultural trade.

It was portrayed as an enlightened policy in tune with the times, which would, coincidentally, make the estate much more money. The powers in the land bought into it, with agencies of government, law and the church all deployed to quell any dissent.

But there was a fight because, as one put it about his people's impending eviction, “It would be as well for them to be killed as set adrift upon the world.”

These people were not in the wretched state many were in later clearances in the west. They were involved in a form of farming which was small scale but successful, with thousands of cattle between them. They could raise money quickly to pay for a lawyer or bail those arrested during their many protests.

What they were being offered in exchange for the good land of the Sutherland interior, in Strathnaver, Strathbrora and the Strath of Kildonan, was two or three acres on rocky outposts such as Strathy Point, where there were no harbours.

The Staffords, and their agents such James Loch and the reviled Patrick Sellar, saw opposition as conspiracy. Sellar described the local population as 'aborigines' and much worse. But neither did Dunrobin Castle like the tenants emigrating, thereby putting a public question mark over the popularity of their humane mission.

It is now almost 40 years since Hunter published The Making of the Crofting Community. Essentially his doctoral thesis, it was the first academic work to challenge those established historians who variously believed that the Highland Clearances never happened; that they had been grossly overstated in oral tradition; or that they were an economic necessity. Since then he has produced more than a dozen other books.

His latest is an achievement, giving life to those who played out the early sad decades of 19th-century Sutherland – both those who were cleared and those who did the clearing. His scholarship is breathtaking.

Every so often it is as though he shakes his head at the enormity of his subject. Of James Loch, effectively the Sutherland’s estate’s chief executive, precisely planning that 704 families were to be cleared in 1819, with another 419 in 1820, Hunter writes: “This meant that, in the course of those two years, something like 5,500 people – men women and children – were to be ordered out of their homes.”

Earlier evictions attracted national attention. At Badinloskin, east of Strathnaver, Margaret MacKay died six days after the destruction of the home she shared there with her two daughters, her son-in-law, and her grand-daughter, aged 11.

The house was set on fire when witnesses said the long bedridden Mrs MacKay was still inside. One of her daughters carried her to the shed where she later died.

Patrick Sellar would stand trial, partly because of Badinloskin. Homes were being set alight by the improvers because if they simply pulled them down, they would be put back up again during the night. But fire was an improvement too far for liberal opinion, being reported in the national press with papers like the Times and the Observer taking an interest. The Staffords themselves would suffer public abuse, shouts of “Fire! Scotland” heard even in Staffordshire.

They largely lived on their English estates, but didn’t like their stewardship of Sutherland being publicly questioned. There was a well-honed rebuttal policy, which some whistleblowers might find familiar today.

Gordon Ross, a Strathbrora schoolmaster, suffered from it. He had the temerity to complain about his sick wife and children, including one two months old, being evicted by men who had been drinking whisky through the previous night. One daughter died three weeks later, but the estate saw to it his name was blackened.

Hunter follows the people from Kildonan across the Atlantic in 1813 and on their epic journey from Hudson Bay to Red River, now Winnipeg, the following year. He is at the Battle of New Orleans, with men who had earlier volunteered in Sutherland for military service, after receiving a pledge their families would not be evicted. Little did they know there was a time limit to the estate’s guarantee.

Almost seven decades had to pass before the people of the Highlands and Islands won parliament's protection from further improvement.

Set Adrift Upon The World: The Sutherland Clearances, by James Hunter (Birlinn, £25)