古代の海の民の足跡Footprints of Ancient Maritime Tribes

In the morning, I had coffee at Hokodo, a historic shop that began selling Uji tea during the late Edo period (1830–1843) and, after the turbulent years of Japan’s opening to the world, became the first coffee shop in Japan to import beans, later restored after its closure, and from there I walked through the former foreign settlement of Kobe, known as the Kyoryuchi in the Meiji era, spending time immersed in the traces of its past. Yet as I was drinking coffee, I recalled that yesterday I had also been researching dotaku (銅鐸), the bronze bells symbolic of the Yayoi period, and it struck me once again that in understanding the three layers of ancient Japanese history—Jomon, Yayoi, and Kofun—representing the major ancestral strata of the Japanese people today, one cannot overlook the existence of the ancient peoples of the sea. Therefore, as part of several ongoing investigations, I decided to shift my means of travel to boats in order to understand the movements of these peoples of the sea, drastically altering my itinerary.

In modern times, following the era of rapid economic growth, we have reached a stage of remarkable development where one can travel at high speed almost anywhere using the shinkansen, airplanes, or highways, and many once-isolated islands have been connected by bridges, allowing for car travel as well. In fact, reflecting on my past seven years of research journeys, nearly all of them were by car. However, from the perspective of tracing the movements of ancient peoples, that method no longer seemed appropriate. Upon researching, I discovered that a ferry operates from Kobe Port to Takamatsu via Shodoshima, so I immediately revised my plans and switched to that route.

The sea route from Kobe to Takamatsu involves a rather large ferry, taking nearly five hours. What makes this route particularly remarkable is that, after leaving Osaka Bay from Kobe Port, it passes through the Akashi Strait, connecting Awaji Island and Akashi, then proceeds into Harima-nada, with the old province of Harima visible to the right, Awaji Island to the left, and Shikoku and Okayama in the far distance, entering the Seto Inland Sea. This provides an excellent opportunity to understand both the movements of ancient people and the shifting nature of the sea. In fact, the currents and changes are evident throughout, prompting one to imagine the routes taken by ancient peoples as they traveled across the waters.

This is because, on the main route into Yamato—where powerful kings once resided—via the Seto Inland Sea from Kyushu, it was necessary to pass through Harima-nada, where knowledge of the complex tides was essential. At that time, unlike today, the coastal areas were not heavily developed, so one must erase the sight of modern towns from one’s mind and imagine the scenery restored to antiquity. Remarkably, when viewed from the sea, one realizes that Japan is surrounded on all sides by mountains. Even amid the vast open ocean, the view from the ship reveals a continuum of low to high mountains, with countless small islands scattered throughout, creating a unique landscape across the Japanese archipelago. This is, without question, one of its greatest features, and maritime technology undoubtedly influenced both the migration of peoples and the formation of culture. Yet as island people, we tend to forget this insular character unless we actually leave for foreign lands.

During this voyage, what I pondered was how these people discovered their ideal lands. For five hours of sailing, I continuously observed the changing scenery outside, reviewing old maps repeatedly, yet it was not something easily understood. Why did ancient peoples cross the seas and settle in certain locations? There must have been some shared indicators they relied upon, though these may have varied by group depending on different origins. Moreover, since the sea level was higher than today, it is believed that majestic landscapes of mountains rising directly from the sea were spread throughout.

This sense of awe brought about by such terrain seems to have been consistent since ancient times. In fact, Chen Shou (陳寿), the author of the Wei Zhi Wo Ren Den (魏志倭人伝), the Chinese chronicle recording the earliest accounts of Japan, was originally from the eastern part of Sichuan Province, so it is possible that he had never seen the sea in his lifetime until then. Thus, the landscape of Japan upon arrival must have been astonishingly different from his homeland, and this dramatic contrast was likely reflected strongly in his descriptions. Furthermore, in older coastal regions such as Sanuki in Shikoku, Harima, Bizen, and Settsu, it is thought that the use of the sea for human exchange was far more dynamic than one might imagine. Indeed, as depicted in the Kojiki and Nihon Shoki, the legendary eastward expedition of Emperor Jinmu (神武東征) set out from Hyuga in search of an eastern utopia, eventually reaching Yamato after generations and finally seizing power as emperors, and they too utilized these same sea routes.

Living in today’s convenient society, it is easy to forget that Japan is an island nation, but by returning to the sea, I feel we can rediscover our roots and draw closer to the mysteries of ancient Japanese history. On this perfectly clear day, gazing at the dazzling sunlight reflected on the sea, I could not help but imagine whether our ancestors too were enchanted by the same brilliance. At the same time, surrounded by mountains on all sides in the middle of a vast sea, I felt as though I had wandered into another realm, gaining a deep sense of the awe experienced by the envoys who studied Japan for the Wei Zhi Wo Ren Den.

One of the greatest insights from this voyage was that mythical concepts such as Tokoyo (常世), Meikai (冥界), and the Yomi (黄泉), which appear countless times in Japanese mythology, can be more fully understood when viewing Japan from the sea.

What is even more intriguing is that, according to ethnological studies, the seafaring peoples and the mountain peoples of ancient Japan may not have been as distinct as later interpretations suggest. There is a hypothesis that the division between those who claimed the sea as their domain and those who claimed the mountains was merely a later construction, while originally, sea-based people may have also lived in the mountains in a cyclical manner. Evidence of this is found in customs that lasted until before the war, where mountain dwellers would craft dugout canoes and present them to seafaring communities. Through rituals, the wood taken from the mountains was transformed into boats, in which the mountain gods were released and replaced by sea gods, embodying ancient traditions of spiritual transfer. These practices convey echoes of very early eras.

Additionally, it is said that mountain people had a “language of the mountain” and seafaring people had a “language of the open sea” (oki), and using the language of the village in the mountains or at sea was considered a defilement of the gods’ realm and had been taboo for thousands of years. This suggests that, since ancient times, Japanese people regarded the mountains and the sea (oki) as sacred places, the very abodes of the gods. From this perspective, it seems that many Shinto rituals and festivals were formed in a cultural environment where sea and mountain were deeply interwoven.

Yet if we go further back in time, both the mountains and the seas must have originally been part of everyday life. Why, then, at some point did mountains and seas come to be sanctified, restricting entry, speech, and customs? By solving this mystery, we may uncover a glimpse into the deeper layers and spiritual world of ancient Japan.