The study reveals that three consecutive years of drought contributed to the ‘Barbarian Conspiracy’, a pivotal moment in the history of Roman Britain. Researchers argue that peripheral tribes took advantage of famine and societal breakdown caused by an extreme period of drought to inflict crushing blows on weakened Roman defences in 367 CE.

The researchers used oak tree-ring records to reconstruct temperature and precipitation levels in southern Britain during and after the ‘Barbarian Conspiracy’. They found that southern Britain experienced an exceptional sequence of remarkably dry summers from 364 to 366 CE, with average monthly reconstructed rainfall in the main growing season (April-July) falling to just 29mm in 364 CE.

The drought-driven grain deficits would have reduced the grain supply to Hadrian’s Wall, providing a plausible motive for the rebellion there which allowed the Picts into northern Britain. The study suggests that given the crucial role of grain in the contract between soldiers and the army, grain deficits may have contributed to other desertions in this period.

The researchers argue that military and societal breakdown in Roman Britain provided an ideal opportunity for peripheral tribes, including the Picts, Scotti, and Saxons, to invade the province en masse with the intention of raiding rather than conquest. Their finding that the most severe conditions were restricted to southern Britain undermines the idea that famines in other provinces might have forced these tribes to invade.

Ultimately, the researchers argue that extreme climate conditions lead to hunger, which can lead to societal challenges, and eventually outright conflict. The relationship between climate and conflict is becoming increasingly clear in our own time, making these findings relevant not only for historians but also for policymakers and researchers today.

In the depths of the last Ice Age, humans relied heavily on fire to survive. Whether for cooking, heating, or social gatherings, fire was an essential tool that played a crucial role in the daily lives of hunter-gatherers. However, despite its importance, surprisingly little well-preserved evidence of fire use has been found from the coldest period of the Ice Age in Europe.

A team of scientists led by the University of Algarve and the University of Vienna has now shed some light on this mystery through an analysis of three hearths at a prehistoric site in Ukraine. The results, published in the journal Geoarchaeology, show that people during the last Ice Age built different types of hearths and used mainly wood, but possibly also bones and fat, to fuel their fires.

The discovery is significant because it reveals a sophisticated mastery of pyrotechnics even in the face of extreme environmental stresses. The analysis shows that humans reached temperatures of more than 600°C, which was possible through careful control and management of fire. This suggests that hunter-gatherers not only used fire for warmth but also as a tool for cooking, making tools, and social gatherings.

One of the most interesting findings is that the three hearths are open and flat, with one being larger and thicker than the others. This suggests that higher temperatures were achieved in this particular fireplace, possibly indicating that people knew how to use fire in different ways depending on its purpose. The analysis also shows that humans used wood as their main fuel during the peak of the Ice Age, with charcoal analyses indicating spruce wood.

The study’s lead author, William Murphree, a geoarchaeologist at the University of Algarve, notes that despite these new findings, the small number of fireplaces from the Last Glacial Maximum remains puzzling. “Was most of the evidence destroyed by the ice-age-typical, alternating freezing and thawing of the soil?” he asks. “Or did people not find enough fuel during the Last Glacial Maximum? Did they not use fire, but instead relied on other technological solutions?”

By further uncovering the role of fire in human evolution, researchers hope to shed light on what is arguably one of the most fundamental technologies that has shaped our species’ success in populating every corner of this planet. The discovery highlights the importance of continued research into the past, and the many secrets that still remain hidden in the archaeological record.

The origins of wealth inequality date back further than we often think. According to a groundbreaking study led by Washington State University archaeologist Tim Kohler, disparities in wealth began to emerge more than 10,000 years ago, long before the rise of empires or the invention of writing. This research, published in a special issue of the Proceedings of the National Academy of Sciences, challenges traditional views that inequality suddenly appeared with large civilizations like Egypt or Mesopotamia.

By analyzing data from over 47,000 residential structures across 1,100 archaeological sites worldwide, researchers used house sizes as a measure of wealth. The analysis revealed that wealth inequality started to increase roughly 1,500 years after the advent of agriculture in different civilizations across the world. This effect was driven by population growth, competition for land, and the development of hierarchical settlements.

“Wealth inequality took root surprisingly early,” Kohler said. “The shift wasn’t instantaneous; it grew gradually as societies expanded, populations increased, and resources became more constrained.” The study highlights several key factors contributing to this phenomenon:

1. Land scarcity: As farming communities grew, land became a finite resource, leading to competition and innovations like terracing and irrigation to boost productivity.
2. Larger settlements: These hubs of economic and political activity concentrated wealth in the hands of a few households.
3. Population density: High population settlements exhibited greater inequality than smaller communities.

One significant revelation is that wealth inequality predates written records, with evidence showing disparities existed even in the earliest agricultural societies. By applying the Gini coefficient – a standard measure of inequality – to ancient house sizes, researchers discovered that early farming villages were relatively egalitarian. However, as settlements became larger and more complex, economic disparities grew.

The study also challenges the idea that preindustrial societies lived in a “Malthusian world” of subsistence-level existence. Instead, Kohler and his team found evidence of steady wealth accumulation and technological advancements over millennia. Early agricultural societies often modified their landscapes to intensify production, which increased productivity but widened the gap between those who controlled resources and those who did not.

Some innovations, like iron smelting, reduced inequality by increasing access to tools and resources for lower social strata, challenging the assumption that technological advances always benefit elites. Kohler noted that other factors, such as large governing systems or collaborative social networks, also played a role in mitigating or amplifying inequality over time.

“This isn’t just a modern problem,” Kohler said. “Understanding the origins of wealth inequality helps us see it as a persistent challenge that societies have been grappling with for thousands of years. The past has much to teach us about navigating these issues today.”

The study was a collaborative effort involving 27 researchers from institutions worldwide and was coordinated by the Coalition for Archaeological Synthesis, a not-for-profit organization dedicated to synthesizing the archaeological record to advance science and benefit society. By focusing on the period before written records, the researchers hope to fill a critical gap in understanding how human societies evolved, from egalitarian hunter-gatherer groups to complex, hierarchical communities.

“These patterns are deeply embedded in our history,” Kohler said. “But by studying them, we can better address their implications for the future. If we can understand how inequality emerged and evolved, perhaps we can learn how to mitigate its impact today.”