Once, not such a long time ago, in colonial New Zealand, Tuhoe were permitted to rule themselves within the boundaries of what was left of their land.

It was the late 1800s and they were the only tribe to gain legal autonomy from the Pakeha Government. For a short while. Then it was taken away.

The desire for autonomy never dulled though, nor was ceded by the Urewera mountain people; and today it is on the table again with John Key's Government, as part of a singular constitutional claim.

In a powerful new book on Tuhoe, eminent New Zealand historian Dame Judith Binney argues for that autonomy to be restored.

The time has long come, Binney told the Weekend Herald. She believes there is nothing to be feared from a separate Tuhoe nation operating within New Zealand and that the tribe has a strong case.

Such precedents exist around the world, she says, from Scotland and Ireland to Catalonia, which has been restored as an autonomous area within Spain, and the large Inuit state of Nunavut in Canada.

Her book makes plain that Tuhoe never wavered in their efforts to retain self-governance, from the moment colonists first began taking their land.

Her book Encircled Lands: Te Urewera, 1820-1921 is a painful, yet compelling, account of the treacherous means used to strip them of their land and subjugate them to Pakeha rule.

The book exposes in meticulous detail, gleaned from historical records and oral histories, the scale of the hurt inflicted by a colonial state hungry for farm land, and driven by the mistaken belief there was gold in the Ureweras.

Within the book's 600-odd pages Binney describes how every method possible - confiscation, war, poverty, sickness, starvation, fraud and ever-inventive legal mechanisms - was relentlessly exploited to take more land.

Just one of the many so-called legal methods used was to insist on surveying land, against Tuhoe wishes, only to charge huge sums for the survey then take the debt back in acres and acres of the best land.

Encircled Lands also rewrites the perception of little-known Tuhoe leaders of the day.

Once considered savages to be feared, Binney says as the men spoke to her unexpectedly across the pages of early records and she got to know them, she found the opposite was true.

She came to admire them as leaders of integrity and determination, men to whom sovereignty was everything.

She remains in awe of them, writing in her dedication these leaders "chose to walk the long paths to peace."

Aside from the nature of the land-grab, which is shocking in its relentlessness and for the poverty which followed, the book may shock in other ways.

Binney also reveals little-known historical evidence which casts doubt on the motivations of one of Maoridom's heroes, lawyer and early politician Sir Apirana Ngata, of Ngati Porou, who Binney says was responsible in the 1920s for taking even more land from Tuhoe, knowing full well their suffering.

The 69-year-old Auckland University emeritus professor anticipates strong reactions to her book from some quarters, but does not shy away from what she has written, hinting in her preface that the narrative she offers "will surprise some readers".

At her home in Mt Eden, Binney explains how her relationship with Tuhoe began in the 1970s.

She knew little of the history when she and some friends set out to walk through the remote Urewera forest to a little place called Maungapohatu they had found on a map.

When they got there they found a collection of derelict buildings, very few people and a feeling they were intruding.

A shiver went up her spine. She could feel the history - a strong sense that here was "a very present past."

She was hooked. Binney had arrived at Tuhoe's sacred mountain where the prophet Rua Kenana, a controversial figure even within Tuhoe, built a thriving religious community in the early 1900s as he tried to restore mana motuhake to his people.

She went away to learn more and has since written a book on Kenana, and another on guerilla rebel Te Kooti, who was to figure so much in Tuhoe's fortunes as he hid out in the Ureweras (she won the 1996 Montana NZ Book of the Year with that book).

Binney says she met remarkable people, including Kenana's children, and gradually uncovered "an astonishing history of pain". She quietly stresses the word "astonishing".

Later, she would be asked to write a report for the Crown Forestry Rental Trust for the Waitangi Tribunal (Tuhoe was this year awarded $66 million in back-dated rental from Kaingaroa Forest interests as part of the "Treelords deal") and it is from that report this book has emerged.

It has been rewritten to be accessible, she hopes, to anyone who is interested in a little-known slice of this country's history and a book 10 years in the making.

In order to understand Tuhoe now, you need to understand the history of their suffering, she says.

In 1866, much of their fertile land was seized by the Crown, cutting off their access to the coast.

A still-hated "confiscation line" was drawn on a map as vast amounts of Bay of Plenty land was carved up for settlers.

Tuhoe had been wrongly accused of being involved in the killings of missionary Carl Volkner and Government agent James Fulloon, and the confiscation of land was said to be punishment for this, but really the land was taken for settlers, says Binney.

War followed the 1866 confiscation. Tuhoe withdrew behind a defended aukati (border) and troops went into the Ureweras inflicting what is known as the scorched earth policy.

They burnt homes and crops - and sometimes their accounts are gleeful.

They forced starvation on people and killed: "They wanted to destroy them (Tuhoe)," Binney says bluntly.

"I mean, I don't know if they wanted to exterminate them, I wouldn't put it like that at all, I think that would be overstating it.

"But there is so much evidence here. They are a small group of people, they're treated with suspicion, they're treated as the savage other from a remote land and this remote land will shelter other people on the run so it's axiomatically of dangerous people.

"That's the starting premise and almost everything swings from that - that these people are dangerous, they've got to be brought under control, pulled out of their mountains.

"In the middle of their fighting everyone had to come out of the mountains. Just stop and think of that for a moment.

"These are people who have been living there since the very beginning and they're told they have to come down out of the mountains and live in a concentration camp or under the supervision of somebody else.

"I don't know anywhere else in New Zealand where it was done like that."

At the end of the fighting, in 1872 a peace was agreed.

Tuhoe understood from the peace agreement they would be autonomous within their rohe potae, a term which likened their encircling boundaries to a hat (potae) placed over a map, thus a tapu covering for the land.

A meeting was held, boundaries worked out and a governing council of 70 chiefs, called Te Whitu Tekau, set up.

They then wrote to tell the then Native Minister, Donald McLean, of their decision.

The tribe had been united and their work was "to carry on the work of this bird of peace and quietness".

They also informed that "the things that were rejected from these boundaries are roads, leasing and selling land."

McLean allowed Te Whitu Tekau to stand and for 20 years Te Whitu Tekau governed, though the Crown constantly attempted to whittle their control away by other means.

Even the New Zealand Herald supported Tuhoe autonomy. In an editorial when then-governor Lord Onslow was due to visit in 1891 the paper wrote that the Queen's writ had never run through the Urewera country and that the country had gone on for 20 years without anybody caring much about the matter.

"Of late they have been perfectly quiet, contenting themselves with preventing all access to their country, and especially keeping an eye on all surveyors, gold prospectors and those who wander about on the 'ragged edges of civilisation'."

All the people wanted to do was be allowed to live in peace on the lands of their fathers, said the Herald, and "as for the Queen's writ, they carry out a better system of self-government than we could give them."

Binney describes the Herald's recognition of Tuhoe's rohe potae as a "breath of fresh air."

In 1896 their autonomy was enshrined in law by the Premier, Richard Seddon, who instigated the Urewera District Native Reserve Act, making the Urewera the only autonomous tribal district that was recognised in law.

It was not to last. This experiment in co-existing legal authorities would be whittled away between 1909 and 1921, says Binney.

There were two reasons. One was a belief an internal self-government could not be permitted, and the other was the determination of successive governments to acquire the ownership of the rest of the Urewera land, which was being eyed not just because of the belief there was gold and minerals, but for tourism.

It is around this time that Sir Apirana Ngata became one of those who played a big part in tearing open the rest of the Ureweras, says Binney.

He and James Carroll, another Maori member of the Liberal Government, implemented that Government's policies for opening up areas of Maori land for settlement.

They were "economic modernisers," says Binney, "working within a framework of the Liberal party's ideology of land development".

But she suspects more was behind their targeting of Tuhoe.

"Both men came from families steeped in histories of recent military conflict with Tuhoe; their sympathies did not lie with the Urewera people on whose behalf they were often presumed to be negotiating, " she writes in the book.

She tells me she was astonished to find out what she did. "I mean, this runs counter to anything that's ever been written about Ngata."

He had been raised in the household of Ropata Wahawaha of Ngati Porou who had led the Ngati Porou contingent in the Tuhoe invasions.

She suspects - but qualifies that she is not sure - that his actions came close to revenge.

He moved people off the land, divided land up and told them they owed, for example, 7000 pounds for the lien on a survey, which they could not pay and which was taken as 29,000 acres.

"In 1922, 68,000 acres of land was taken by Ngata's demand for things that he said they had to pay. That's on top of what the Crown claimed it owned and had bought, which was more than two thirds of the reserve.

"Now, that's Ngata acting as the agent for Tuhoe in 1922. Come on, I think it's terrible."

Ngata was young and very bright, with clear ideas about getting Maori economically activated in the modern world, she says, and he became very important to Maori.

"But it still doesn't explain why he drives Tuhoe from their land in the way that he did, what was left of their land."

Since those days, Tuhoe have again been persecuted by the Government, Binney believes.

In 2007 armed police lined up along the confiscation line, the defended border of the first aukati, when they conducted the so-called terror raids, for which she says no evidence has been revealed.

But by lining up here the police actually endorsed the existence of the rohe potae, she writes in the book.

"The line is a frontier again: this is not an illusion."

Judith Binney's Encircled Lands: Te Urewera, 1820-1921 ( Bridget Williams Books, $79.99) is in book stores on Monday.

Dame Judith Binney says the history books have it wrong about some of the early Tuhoe leaders to whom she dedicates her book, including Te Whenuanui I, Te Makarini Tamarau, Erueti Tamaikoha and Kereru Te Pukenui.

Erueti Tamaikoha, for example, has been described as a ferocious warrior, a savage and a cannibal but Binney says he was a man of integrity.

"I got the sense of this huge man with commitment and a wonderful spirit.

"People liked him. Everybody knew him and liked him and some of the Pakeha who were terrified of him who got to know him always spoke well of him after the wars."

There were good reasons for the fights he was involved in, she says. They began after the confiscation of vast amount of land in 1866 and coincided with the announcement of the aukati (defended border) a year later.

Binney says sometimes her eyes "stood out on stalks" at what she was reading in the research for her book. Two examples were what she calls the scandals of Waiohau 1B and Tahora 2, large blocks of prime land obtained by fraud.

The loss of Waiohau 1B led to the people of the Te Houhi settlement, who had been peacefully occupying their land, being evicted. Tahora 2 was obtained through an unauthorised private survey which became a Government-enforced lien placed over Tuhoe lands.

When in April 1889 the land court ruled the owners must pay the survey costs, Tamaikoha called the ruling an "act of oppression."