Japan was born fifteen million years ago, pushed away from the edge of Eurasia by the formation of the Japan Sea. At the time it was quite flat, but it sits at the confluence of three massive tectonic plates—the Eurasian, the Pacific, and the Philippine—which mashed together to buckle and warp the land into towering mountains. These heights, young in geological terms, created steep watercourses and fast rivers that rushed down toward the sea, dragging sediment with them.
Elsewhere, the tectonic plates were forced downward. Only a million years after Japan was first formed, its first volcanoes burst into life, peppering the landscape with its oldest craters. Two million years ago, the northern part of the island of Honshū was ripped apart by huge eruptions, the scars of which still form circular lakes and ridges, some miles wide. The map of Japan remains dotted with suspiciously round lakes and islands, or curved bays that indicate the forgotten edge of ancient craters. Even in the era of human settlements, occasional disasters have depopulated entire regions. Parts of Japan have been settled “for the first time” on multiple occasions, the newcomers being unaware that the bones of earlier inhabitants lay beneath their feet, under layers of ash and mud.
Even today, a tenth of the world’s active volcanoes can be found in Japan. Throughout its history, the nation’s geographical situation has led to periodic disaster—not merely volcanic eruptions, but landslides caused by the precarious purchase of soil on its steep mountains, and earthquakes from the continued push and shove of underground forces. From Japan’s times of legend through to the modern era, there are tales of entire mountains falling into the sea; of new islands born from a flaming abyss; of the ground tearing itself apart only to invite great, overwhelming inrushes of the sea. It is no coincidence that tsunami is a Japanese word. Once every 800 to 1,100 years, for example, the sediments of north Japan show the evidence of a “tsunamigenic” deposit—a thick layer of mud left behind by an immense flood from the sea, caused by an offshore earthquake in a fault line to be found 70 kilometers (43.5 miles) away on the sea bed. Court chronicles in 869 CE reported an earthquake and an onrushing tidal wave that killed a thousand people and wiped out the garrison town of Tagajō. It would be 1,142 years before the process repeated itself in 2011.
Japan confounds all expectations. It never fails to surprise. Modern visitors can still be shocked by how green it is—even now, one of the local names for the land is the Green Archipelago (midori no rettō). True enough, contemporary cities are all too often a charm-less jumble of skyscrapers and storm drains, their landscapes ruined by big-box supermarkets. But Japan’s cities huddle on a remarkably small area of land, much of it only reclaimed from the sea in the last century. Tōkyō, Nagoya, and Ōsaka occupy the only large areas of flat terrain in the whole country south of Hokkaidō: the plains of Kantō, Nōbi, and Kansai. Even these, however, are relatively small by global standards.
Inland, more than two-thirds of Japan’s area comprises uninhabitable mountains, thickly forested today with non-native trees. In prehistoric times, the land was covered in woods of evergreen oak, hinoki cypress, and camphorwood. It was these native trees that supplied the lumber for the earliest Japanese buildings, although today they are so rare that they are usually only found on holy ground, preserved within the precincts of temples and shrines. These forests were rapaciously destroyed by the middle of the Dark Ages, cleared to meet a rising need for farmland and for firewood as fuel in a land with poor-quality coal, but also felled for building material. Eschew-ing stone for most construction, the Japanese preferred to work with wood. The largest wooden building ever built, the great Buddhist temple of Tōdaiji in Nara, required 900 hectares of forest—about nine square kilometers. And wooden materials need regular replacing, which ensures not only continued drains on resources, but also means that much of “old” Japan is actually more recent.
By the time the Japanese first began to write down their own history, those ancient forests were disappearing, replaced by red pines, deciduous oaks, and greater concentrations of chestnut and walnut. This modern appearance is also the result of a bold, concerted effort at reforestation dating from the sixteenth century, when Japan’s overlords realized that the continued plundering of the hillsides would have a disastrous effect on farming. Just over half of Japan’s land area is forested today.
Japan is also a long country: its southernmost reaches in the Ryūkyū Islands share the latitude of the Bahamas; its northernmost point in Hokkaidō matches that of Quebec. Although recent centuries and the draconian codes of the samurai have forced a certain homogeneity of culture on the Japanese, with regional differences often confined to genteel subtleties of clothing or refined differences in cuisine, ancient Japan was much more diverse, spanning everything from subtropical islanders to snowbound bear hunters.
Japan’s latitude places much of its land mass closer to the south than much of Europe, making it substantially warmer than those countries that decided the norms of a temperate climate. It is also wetter—even in the middle of Japan’s Alps, you are never more than 100 kilometers (62 miles) from the sea; humidity is high and summer rains help a strong growing season. This, in turn, means that swings in global climate can often have the opposite effect in Japan than in those latitudes where most English-language historians live. When global temperatures took a turn for the warmer, European historians celebrated Roman vineyards in England and Viking colonies in Greenland, but Japan suffered droughts and disease. When global temperatures dropped and Elizabethan Londoners looked out glumly on a frozen Thames, a cooler, more temperate Japan experienced a boom in agriculture and population.
One of the most crucial elements of Japanese geography has been the size of the Korea Strait (known in Japan as the Tsushima Strait, so named for the island in its middle) that separates it from mainland Asia. With a width of 200 kilometers (124.5 miles) at its narrowest point, this body of water arguably keeps Japan at a perfect “Goldilocks” distance—not so far as to make it impossible to trade and communicate, but far enough to prevent most large-scale military operations. The crossing was safe enough for a premodern ship that could afford to wait out storms in a safe harbor, but famously deadly to an armada of hostile enemies with no safe port.
Humans first arrived before the strait was formed. At the end of the last Ice Age, southern Japan was linked to Korea first by a land bridge and then, for some time, by a strait narrow enough to make the opposite shore tantalizingly visible. In the far north, Japan was linked to Siberia by a similar land bridge that connected Hokkaidō to Sakhalin and the Russian coast. To the south, the Ryūkyū Islands were larger, and mostly within sight of each other, all the way from proto-Taiwan to the edges of the Japanese mainland. Settlers hence approached the region from both north and south.
Somewhere off the Japanese coast, no doubt, there are multiple archaeological sites that were once home to these forgotten peoples, now drowned beneath the waters that rose at the end of the Ice Age. Unfortunately, these areas also formed much of the flat plains that afforded hunting opportunities for big game: the grasslands where the ancient Jōmon people once hunted bison, for example, are now beneath the sea.
Their descendants wandered inland, into the river valleys and the coasts. In the far north of Honshū, Aomori Bay offered a vast foraging area for crustaceans, fish, and seaweed. In the south, the straits between the islands of Honshū, Shikoku, and Kyūshū formed an idyllic Inland Sea, protected from storms but rich in marine life. The currents forced through these passages sometimes created treacherous whirlpools—in Japanese, naruto—but otherwise the Inland Sea was, and still remains, a beautiful patch of gentle water, scattered with green islands.
This protected waterway has had a powerful influence on the development of the Japanese state, encouraging marine commerce and transport links. Where there are fishermen there are fishing boats, and where there are boats there are easy links to transport produce and goods to the next island and across the horizon.
Excavations of ancient graves find bodies dusted with red ochre (an adornment mentioned in some Chinese sources), and an aristocratic class of women wearing single-piece shell bracelets too tight to be removed and too delicate to allow for the possibility of manual labor. Whoever these women were, they presumably donned their bracelets in childhood and left them on permanently thereafter, suggesting a class of priestesses or shamans who were not expected to hunt or gather.