This image is commonly reputed to be Pemulwuy, an Aboriginal warrior, but it is, in fact, an unidentified North Queensland warrior photographed by Henry King in about 1900. Even if a government had sought out such information the task would have been immensely difficult. Much of the killing happened on the edge of settlement in regions remote from the reach of authority. Because there was no official recognition of a state of war any killing was technically murder. Frontier communities were notorious for keeping secret their exploits in the war. Killing was referred to using a lexicon of known euphemisms. Punitive parties may often not have known how effective their attacks were, particularly when they operated in the dark or if they shot at groups some distance away. When the bodies of victims were encountered they were almost universally burnt to destroy the evidence. The long career of the Queensland Native Police was cloaked in official secrecy and most of the records were destroyed. If it is difficult to determine how many people died in direct conflict with the settlers. It is even harder to estimate how many more must have subsequently died of wounds or from the fierce rigours of prolonged and uneven warfare. There was considerable interest in the question in the late 19th century but as the Aborigines themselves disappeared from the historiography of the first half of the 20th century, no one seems to have thought it an important matter for speculation. With the new interest in Aboriginal history that arose in the 1970s and 1980s attempts were made to assess how many people, both white and black, died in the frontier wars. In my book The Other Side of the Frontier (1981), I argued that it was ''reasonable to suppose that at least 20,000 Aborigines were killed as a direct result of conflict with the settlers''. Twenty years later this estimate became one of the points of contention in the series of controversies known as the history wars, with suggestions that such interpretations were part of a widespread attempt to ''fabricate'' an inaccurate and partisan version of Australian history. The one enduring effect of the intense controversy was to stimulate new research and encourage the reconsideration of previous work on frontier conflict. We are now a little closer to understanding the full impact of the frontier wars on Aboriginal society, with the appearance of new scholarship dealing, in particular, with Tasmania, South Australia, Queensland and the Northern Territory and covering the years from the 1820s to the 1880s. The most striking new work appeared in Frontier Justice: A History of the Gulf Country to 1900 by Tony Roberts, published in 2005. While focused on one region - the eastern part of the Northern Territory to the south of the Gulf of Carpentaria - the work has much wider significance. It is the product of 30 years of research, during which Roberts travelled over the country, interviewed old residents both black and white, and followed the paper trail in the relevant archives and libraries. The result is a compelling picture of the era of pioneer settlement and conflict between the invading frontiersmen and the roughly 3000 resident Aboriginal people, who were divided into 15 discrete language groups.

Historian and author Henry Reynolds: "Much of the killing happened on the edge of settlement in regions remote from the reach of authority. Because there was no official recognition of a state of war, any killing was technically murder." Credit:Justin McManus Pastoral occupation began with a spectacular surge in the early 1880s, when the distant South Australian government threw the whole region open for settlement. The sudden invasion of the white men and their horses and cattle was a traumatic experience for the resident bands. They lost the capacity to follow their traditional patterns of travel, land management, hunting and food gathering within weeks of the invasion, and were often forced to retreat into the most marginal country in their homelands where water was scarce and the food quest arduous. They had realistic fears of walking in open country. Men were shot and women abducted. Roberts carried out the most detailed and exhaustive surveys of the killing fields. He is able to list 53 sites where there were ''multiple killings'' of Aborigines but assumes there are many more he does not know about. At least 600 men, women and children died violently, or about one-fifth of the pre-contact population. The death toll could have reached 700 or 800. Thirty Aborigines died for every white man killed. Disease played no part in this massive, disproportionate loss of life. As a result of territory-wide research, Roberts has concluded that at least 3000 Aborigines died in conflict with the invaders of their homelands. Queensland remains the colony that saw the most intense and enduring conflict. Several reasons can be readily suggested for this situation. The colony was huge, roughly 1.8 million square kilometres, and almost all of it able to support substantial Aboriginal populations totalling perhaps 200,000 divided into well over 100 tribal groups. The whole landmass was equally able to support a variety of European industries, but their establishment was protracted, occupying the whole second half of the 19th century. Throughout much of this time - from 1856 to 1900 - political control was in the hands of the colonists themselves. The restraining, albeit distant, and compromising voice of the imperial government was silenced. The Queensland frontier has attracted renewed interest since the contention of the history wars. Jonathan Richards has produced a meticulous study of the Native Police force and Robert Orsted-Jensen has completed a massive study of the frontier wars. Ray Evans, the doyen of Queensland historians, has returned to the same subject he has worked on for more than 30 years. The renewed scholarship has reinforced the interpretation of the Queensland frontier as a site of vast brutality and mass killing.

Richards argues that the Native Police force was created ''to kill Aboriginal and Torres Strait Islander people in Queensland'' and as a result lies ''close to the heart of European Australia's dark nation-making origins''. He stresses that it was essentially a military organisation rather than a normal police force. Orsted-Jensen's study complements Richards' book, establishing beyond reasonable doubt that violence accompanied the expansion of settlement in Queensland and that this was known, openly discussed and accepted by colonial leaders in politics, business and the press. Orsted-Jensen makes clear that the activities of the Native Police were well understood, as was the widely used term ''dispersal'', which unambiguously referred to the practice of shooting indiscriminately into Aboriginal camps. Colonial opinion embraced the view that such punitive action was a necessary accompaniment to successful colonisation. It was also widely accepted that when Aboriginal bands killed or wounded settlers it was imperative to take severe retaliatory action, killing widely and disproportionately. There was a widespread understanding that the colony was engaged in a kind of warfare. Orsted-Jensen also shows that there was a persistent debate about the need to exterminate the hostile tribes. His richly documented work shows that not only was Queensland distinguished by the extent of frontier violence, it also provides the researcher with a rich source of contemporary commentary. The many newspapers often contained reports or letters that provide detail of brutal Native Police action or violence of settlers, along with a constant stream of reports about Aboriginal hostility. The frontier newspapers have an immediacy that makes for compelling reading. Ray Evans has recently returned to the subject of frontier violence, taking on the difficult and contentious task of assessing the number of Aborigines killed in frontier warfare and more specifically the death toll that can be attributed to the Native Police. This has always been a vexed issue. The force, as is well known, patrolled the frontier for decades, and throughout its history it rarely arrested, imprisoned or brought to trial any suspects. It is also known that the white officers were required to provide regular reports of their patrolling activity to police headquarters in Brisbane but that the great majority of these reports have not survived. Evans begins by calculating the extent of the force's activities from what we do know. Between 1859 and 1898, 85 camps were established and existed for varying periods, although the average camp life was seven years. During that time, detachments of the force conducted regular monthly patrols. In all there may have been as many as 7000 patrols, but Evans decides to work with a minimum figure of 6000. From there he uses the surviving records of 22 monthly patrols conducted in central and north Queensland between 1865 and 1884, during which the officers recorded 57 collisions or dispersals - an average of 2.6 engagements per patrol. The officers recorded incidents but not usually the numbers killed. As Evans points out, however, even with a conservative assumption that only two people were killed in the average dispersal, ''we find ourselves confronting an aggregate estimate of 24,000 violent Aboriginal deaths at the hands of the Native Police between 1859 and 1897 alone''.

This figure takes no account of deaths due to the action of the settlers themselves or of those that took place before the separation of Queensland from New South Wales in 1859. Commenting on these figures, Orsted-Jensen suggested they ''confront us with powerful indications that we could well look at a total which by far exceeds 30,000 Aborigines killed in conflict with settlers in Queensland during the 19th century''. These figures are historically plausible, cogently presented and immensely challenging. But the sharpest debate at the time of the history wars was about Tasmania, where a very different story unfolded. The major conflict took place from 1826 to 1831. While we have precise figures for white deaths in conflict, the Aboriginal death rate has often been a subject of controversy. The problem is compounded because we are uncertain of the size of the original population, with estimates ranging from 3000 to 6000 for Tasmania. What we do have is a precise count of those who survived the conflict and a reasonable estimate of the numbers in the early 1820s before the war began. Recent research has determined that all the available accounts of conflict indicate that about 350 Aborigines were killed but that the total death toll may have been as high as 1000, most of them killed in unrecorded nocturnal raids by vigilante groups. The estimates made about the cost of war in Tasmania are broadly consistent with the assessment made about early Victoria by Richard Broome in his 2005 book Aboriginal Victorians. He concluded that hundreds of violent clashes occurred across the grasslands during the decade of European invasion. Over that time of conflict, 70 or 80 settlers were killed and perhaps 150 injured. Using a range of studies Broome attempted to arrive at a reasonable figure of Aboriginal casualties and concluded that ''a total figure of a thousand black deaths at white hands is likely''. Loading A compilation of regional studies does not allow us to assess the overall death rate in Australia's frontier wars. But some things are clear. Aborigines were killed by settlers every year somewhere in Australia from 1788 to the early years of the 20th century, and died in disproportionate numbers. The research of the last decade has led most engaged scholars to conclude that the controversial 1981 estimate of 20,000 Aboriginal dead needs to be revised not downwards but steeply upwards to 30,000 and beyond, perhaps well beyond. And the dead do matter. They intimidate us. They force us to reassess many other aspects of Australian history. That is the least that can be done.

This is an edited extract from Forgotten War. It is published by NewSouth and won the 2014 Victorian Premier's award for non-fiction. Henry Reynolds is a Tasmanian historian.