The Origins of the Yayoi People in the Xinglongwa Culture of the Xiliao River｜The Liao Civilization and the Sannai-Maruyama Site

“The Jomon people became the Yayoi people.” You see explanations like this again and again in archaeological museums across Japan. But what on earth does it mean for the Jomon to become the Yayoi?

Recent genetic research has begun to suggest that the Yayoi people had decidedly complex roots. The Yayoi were not simply the Jomon under another name. Some mixing with the Jomon does appear, but they were also an independent people with no relation to them, and their makeup is multilayered, built up from several strata.

At the very earliest layer of those roots lies a mysterious ancient civilization known as the Xinglongwa culture (Koryuwa in Japanese). It appeared around 6200–5400 BCE in the basin of the Xiliao River, which stretches from what is now southeastern Inner Mongolia to western Liaoning Province in China, and it can be regarded as the “place of beginnings” that laid down the genetic substratum of the Yayoi. Its people later dispersed in many directions, but those who stayed behind built the current known as the Liao civilization. Here is a brief outline of its chronology and character.

◯Xinglongwa culture (c. 6200–5400 BCE)
China’s oldest jade ornaments, such as earrings, have been excavated here, along with artifacts shaped like dragons. Jade ornaments were also used actively in ritual settings in Japan from the Jomon period on, whereas the dragon reached Japan only in the Yayoi period. In their way of life, these people formed a base population that began cultivating millets such as proso and foxtail millet, and they had no wet-rice farming. They were also among the earliest to build planned settlements enclosed by moats, with a ditch dug around the perimeter. These cannot be joined in a single straight line to the moated settlements of the later Yayoi, but there is a visible echo between them, since this is a settlement form that settled farming societies tend to arrive at.

◯Zhaobaogou culture (c. 5400–4700 BCE)
Here, dry-field farming centered on millet was combined with hunting and gathering. Pottery has been found bearing geometric patterns and finely incised drawings that seem to deify deer, boar and birds, which suggests that the ritual beliefs leading to the later Hongshan culture were beginning to take shape. The Yayoi, in fact, had a custom known as pictorial pottery, on which they drew the memory of their origins, their lives and their roots. Such pictures are not found in the Jomon period. And where Jomon animal worship centers largely on the boar and the snake, the Yayoi are distinctive in making the deer and the bird their objects of worship.

◯Hongshan culture (c. 4700–2900 BCE)
Personally, I see this as the group that formed the cultural and spiritual substratum of the Yayoi. Unlike the cultures before it, ritual came into full flower here, and ritual groups from tribes that worshipped a goddess may have risen to prominence. At the time, the region enjoyed its mildest climate, blessed with rich forests and rivers, and the foundations for prosperity were in place. Yet it was also an age in which climate change was gradually making the old way of life hard to sustain. The tribes split apart, but it seems that, to keep their old memories alive in common, they gathered at particular times of year, such as the spring and autumn equinoxes and the summer and winter solstices, and held great rituals that brought many tribes together. Himiko, the famous queen of the Yayoi period, may stand downstream from the source of such beliefs.

◯Xiaoheyan culture (c. 2900–2200 BCE)
Severe cooling and drying, in effect desertification, set in, and the enormous rituals that had sustained the Hongshan culture could no longer be kept up, so that culture collapsed. The splendid jades and large ritual structures that had symbolized Hongshan disappeared, and people returned to a smaller, more practical way of life. This structural shift from large settlements to dispersed ones was in fact also happening in Japan at the time, which can be taken as evidence that climate change was under way on a global scale. In the course of it, the question became how to keep alive the spiritual bonds that had grown up in the age of large settlements.

◯Lower Xiajiadian culture (c. 2000–1500 BCE)
This is the stage at which the main line of the Liao civilization comes to a close. Interestingly, even as climate change grew harsher still, population density actually rose, and the social structure was transformed. A custom unknown to the earlier Liao civilization appeared, that of building settlements on cliffs and steep slopes, and people began ringing them with sturdy “stone castles,” walls of piled stone. They took up weapons as well, and society turned into a tense, militarized one in which tribes waged fierce struggles for survival and wars of defense against one another. This points to an incursion of foreign peoples driven by climate change.

◯Upper Xiajiadian culture (c. 1000–600 BCE)
What appeared next in the same Xiliao River country was the Upper Xiajiadian culture, and its character was very different. It was a mixed society of farming and herding, and it developed the technology of bronze, the key to the Yayoi period, making ritual implements from an alloy of copper mixed with tin and other metals. What deserves attention is that in this period the bearers of the culture themselves changed. The lineages that had been most frequent from Hongshan through the Lower Xiajiadian period gave way, in the Upper period, to groups closely tied to the Han Chinese and to groups that included Mongolic peoples. In the homeland of the Liao civilization, in other words, a mixing was under way in which East Asian lineages were laid over an older Northeast Asian stratum. And it is precisely the culture of this Upper period that has Yayoi-like features. Perhaps this group moved south in a single wave and crossed all the way to the Japanese archipelago.

Seen as a whole, the cultures from Xinglongwa to Lower Xiajiadian form a single civilization around the Liao River that lasted from about 6200 BCE to about 1500 BCE, and its main line was finally wiped out by the arrival of foreign peoples. The Roman Empire, too, after its great prosperity, was undone by climate change and internal corruption and fell at last to the invasions of the Germanic peoples.

Worsening climate change, then, and the foreign invasions that came with it were what ended the Liao civilization, and this is a code of endings that runs through civilizations all over the world. Yet those grand millennia also drove the people of the Liao civilization to disperse, and they scattered, quite literally, in every direction. Some of them, by complex routes, eventually began to arrive in Japan as well, and on the Japanese side there is a site whose story closely resembles that of the Liao civilization from its heyday to its end. It is the Sannai-Maruyama Site in Aomori.

The Sannai-Maruyama Site, the largest settlement of the Jomon period, flourished from 3900 to 2200 BCE, until at a certain point the settlement was abandoned and its people vanished without a trace. Several hundred people are thought to have lived there at its height, and what they left behind makes plain how prosperous it was. The intriguing thing is that we still do not know where they went.

Around the time Sannai-Maruyama was abandoned, on the other hand, there appear large ritual spaces known as stone circles, with stones set out in a ring. They are a custom unique to Hokkaido and northern Tohoku, and they too remain unexplained and shrouded in mystery. In the same period, however, Jomon communities across northern Tohoku abandoned their large settlements one after another. It looks as if they sensed what severe climate change would bring and reorganized themselves, their families and their groups into systems built purely for survival. The greatest trait of the Jomon people, and one rarely spoken of, is their capacity to survive.

They broke up into small groups and moved, above all, into river valleys, but it seems that at certain times of year they gathered at the stone circles to hold rituals, keeping alive the spiritual bonds with other groups that they had formed in the age of large settlements. Indeed, on a hill 8 km south of Sannai-Maruyama lies the Komakino Site, a huge stone circle, which suggests it may have been where the groups connected with Sannai-Maruyama came together for shared rituals after they dispersed.

They could not, of course, have known about the upheavals on the continent and the peninsula. Yet in the same period, across the sea around the Xiliao River, climate change and foreign invasion were causing great disruption, and this is thought to have led, in time, to the dawn of the Yayoi period. What also matters is that the Yayoi were not simply the people of the Liao civilization. They carry it as a substratum, but they are considerably intermixed.

Research in the early 2020s sorted things into a simple three-layer structure, with the Jomon as indigenous, the Yayoi as Northeast Asian, and the Kofun people as East Asian. From around 2024, however, studies on the Japanese side have cast doubt on this neat classification, and researchers have begun to point out that by the time of the Yayoi, mixing between Northeast Asian and East Asian ancestry had already gone a long way.

The effort to trace a people’s roots through genetics has only just begun, and it is an unknown field that will advance greatly as studies accumulate. At the same time, uncovering those roots cannot be separated from the international situation peculiar to East Asia. The Japanese archipelago cannot be studied on its own. To trace the roots, the reunification of Korea is, at the very least, an absolute precondition, and only after decades of archaeological work on the North Korean side and joint research across East Asia, led by China, will the reality finally come into view. The greatest obstacle to uncovering our roots, in other words, is international politics.

Where did we come from?
Whether we ever reach an answer to this most fundamental of questions may, in every age, depend on the designs of those in power.