Ringed by the high peaks of the Tian Shan ‘Mountains of Heaven’ to the north, the Altun Mountains to the east, the Kunlun Mountains to the south and the Pamir Mountains to the west lies the Tarim basin. A basin is simply a geological formation characterised by a low-lying area. In this basin lies the Taklamakan Desert – one of the most inhospitable places on earth, and the second largest pure sand desert in the world after the near-endless sands of the Arabian Peninsula. Temperatures range from 40 degrees Celsius in summer to -20 degrees Celsius in winter. Its name is taken from an old Persian saying which means “Place of No Return”.

In the early 20th century, some of the desert’s secrets were uncovered by western explorers along its southern and eastern edges. In the last decades, Chinese researchers have uncovered more. Under these shifting sands lie a series of tombs, numbering in the hundreds and dating as far back as 3,800 years to the Bronze Age. These tombs contain incredibly well-preserved bodies that have a European-like appearance. Even more remarkably for a desert, the bodies are buried in wooden boats and dressed in leather and wool clothing. Though they are often referred to as mummies (and I will continue to refer to them as such), they are really desiccated corpses. No process was undertaken to preserve these corpses. Rather, the natural environment of the Taklamakan Desert, with its extreme aridity and the high salt content of the soil prevented the decomposition of the bodies to a remarkable degree. The bodies are so well preserved that tattoos and paint on the skin can still be seen.

Though almost no one is mad enough to live here today, thousands of years ago the Tarim basin would have been a lush river oasis containing wealthy city-states integrated into the Silk Road trade route. Merchants traded ivory, precious stones, glassware, silks and spices. Water from the winter snows melting on the surrounding mountain ranges would have flowed into the lowland, creating a vast river system flowing throughout the area. There was a lake called Lop Nur which was fed by these melts. These rivers were constantly shifting course – it is likely that this population was suddenly stranded when the river they depended on abruptly changed course.

Because of their European-like appearance – they had blond, brown, and red hair and large noses– they were assumed to be the remains of an Indo-European group that had genetic roots in Europe. The Indo-Europeans were a group of Steppe pastoralists who expanded from their lands in the Pontic-Caspian steppe – what is today in the south of Ukraine and Russia – across Eurasia, beginning approximately 4,000 years ago. They spread their genetics and their language from Britain to India as they conquered.

The mummies were thought by some to be Tocharians – an Indo-European descended group that spoke Tocharian. Tocharian is the second oldest Indo-European language, after Hittite, to branch off from Proto-Indo-European (PIE). PIE is the language of the Indo-Europeans in their homeland in the Pontic-Caspian steppe. Their clothing - bright, elaborate and fashioned from wool, furs, or cowhide - also suggested ties to European cultures – some wore pointed hats, resembling those worn by witches. One of the mummies, Chärchän Man, was red-headed, wore a full beard and was buried wearing a tartan skirt reminiscent of the Celts.

The presence of kefir cheese indicated that the group practised pastoralism, but they were also buried with wheat, barley and millet grains, indicating they farmed – or traded with farmers.

The unknown origins of the earliest inhabitants of the Tarim basin have been a point of contention in modern China. Their presence in the Xinjiang region of western China has been a rallying call of the Uyghur people – a Turkic-speaking group that is largely Muslim – who are persecuted by the Han Chinese. The Uyghurs consider the mummies, like The Beauty of Loulan to be their ancestors. Loulan was an ancient city and kingdom built around an oasis in the Tarim, as well as being part of the Silk Road. The Beauty of Loulan is a woman who was among the first mummies to be discovered in the region. She has been dated to about 1800 BCE. A genetic connection to the Tarim mummies would prove their historical claim to the land. Chinese authorities, perhaps because of this, have been reluctant to allow genetic testing on the mummies.

Chinese officials needn’t have worried that the mummies would have a Uyghur connection. The Uyghurs only arrived in the Tarim basin in AD 842 - many centuries after the Han Chinese. But the mummies are not Han Chinese either. So, who were these people?

It was only in 2021, with the release of new genetic testing, that the mystery of these mummies was finally solved. The Tarim mummies were confirmed not to be Indo-European descendants, but an isolated group that was descended from Ancient North Eurasians (ANE) and West Siberian Hunter-Gathers (WSHG) – who themselves were largely ANE descended. The Ancient North Eurasians were an Ice Age population that was indigenous to Northern Eurasia about 9,000 years ago.

It also shows the likely origin of Tocharian in Asia is in the Dzungarian basin just north of the Tarim basin. The samples from the Dzungarian are also older than those in the Tarim which means that the Tocharian languages moved south into the Tarim basin quite late.

The mummies show little genetic admixture, which means they did not inter-marry with any of their neighbouring groups, but they did adopt their clothing, their animal husbandry and their cheese-making. They also learned how to farm wheat - originating to the west - and millet - originating from the east. This combination of pastoralism and agriculture allowed them to thrive in the oases of the desert.

They were the last of their people. As their oases died, so did they.