The 16th and 17th centuries marked the apex of Ainu civilization—a period when their culture flourished, their influence reached far beyond the coasts of Hokkaido, and their traditions acquired a remarkable depth and vibrancy. While the encroachment of the Matsumae domain and Japanese traders continued, this era also saw the Ainu assert their identity with renewed vigor, drawing from ancient roots while embracing the opportunities and challenges of a changing world.

At the heart of this golden age stood the kotan, now larger and more prosperous than ever before. Archaeological surveys reveal that these settlements, typically arranged along riverbanks or coastal margins, grew more complex in layout during this period. Rows of thatched-roof homes faced communal open spaces, where villagers gathered for rituals, trade, and feasting. Storage pits lined with bark and woven reed mats preserved abundant harvests of millet, beans, and foraged nuts, while smokehouses and drying racks, constructed from local cedar and elm, stood as permanent fixtures near the riverbanks. The air would have been thick with the scent of smoked fish, cedarwood, and earth—a sensory tapestry that spoke to both the abundance and the practical ingenuity of Ainu daily life.

Village life thrived in these years. Fishers hauled in abundant salmon, char, and trout from the rivers, using hand-crafted nets and bone-tipped harpoons whose design is attested by finds in both burial and habitation sites. Women skillfully wove attus cloth from elm bark, a process involving soaking, pounding, and weaving, with finished garments displaying distinctive patterns that archaeological textile fragments confirm were both beautiful and functional. Children played in the shadow of these homes, learning to recognize the calls of birds, the movements of animals, and the cycles of plant life that structured the year. Food preparation, as evidenced by grinding stones and large communal mortars, was a communal affair, with grains and nuts pounded into flour and pastes for feasts that reinforced social bonds.

Material culture reached new heights: excavations from this era attest to a richness in both everyday and ritual objects. Intricately carved wooden implements—some used in ceremonies, others in domestic life—displayed motifs of bears, owls, and orcas, reflecting spiritual beliefs tied to the natural world. Lacquered bowls and storage containers, often imported through trade with Japanese domains, signal both wealth and a cosmopolitan taste. Ironwork, ranging from fishhooks to decorative knives, has been recovered from sites across Hokkaido, suggesting a wide network of exchange that extended to Russian Siberia and beyond.

Trade reached its most sophisticated form during these centuries. The Ainu became renowned as master middlemen, facilitating the flow of goods between the Japanese, the peoples of Sakhalin and the Amur, and even distant Russia. Furs, particularly those of sable and sea otter, were prized commodities, and eagle feathers—essential for samurai regalia—were exchanged for rice, sake, and metalware. Evidence from port records and Ainu oral histories reveals that some leaders amassed considerable wealth and prestige, using it to sponsor festivals, support warriors, and commission the creation of stunning ritual objects. Archaeological evidence of imported ceramics and coins, as well as the remains of specialized workshops, further attests to the intensity and organization of Ainu trade during this period.

Religious and artistic achievements blossomed in this era. The iyomante, or bear-sending ceremony, reached new heights of complexity, combining elaborate processions, music, and offerings to invoke the favor of the kamuy. Excavations of ceremonial sites have unearthed wooden inau (prayer sticks), their shavings intricately curled and painted, and ceremonial ikupasuy (ritual wands), some inlaid with bits of copper or shell. These objects reveal not only spiritual devotion but also artistic innovation—each kotan developing local styles and techniques. Oral epics—yukar—were recited by skilled storytellers, weaving together myth, history, and moral lessons in performances that could last for hours, their words echoing through firelit halls and reinforcing a shared sense of identity and tradition.

Daily life during this period was marked by both abundance and structure. Women held significant authority within the household and in matters of ritual, their knowledge of medicinal plants and textile arts highly valued. Children learned hunting, fishing, and the stories of their ancestors from an early age, their education shaped by the cycles of nature and the needs of the community. While social hierarchy remained relatively flat compared to neighboring cultures, the growing importance of trade and ritual leadership did create new distinctions within Ainu society. Archaeological indicators—such as the presence of imported goods and ceremonial regalia in certain burials—suggest the emergence of prominent families and ritual leaders, whose influence extended across several villages.

The Ainu’s diplomatic acumen was on full display during this golden age. Leaders negotiated treaties and trade agreements not only with Japanese officials but also with Russian explorers and Siberian tribes. Some kotan formed loose confederations for mutual defense or economic advantage, while others maintained independence through careful balancing of alliances. Records from the Matsumae domain indicate periods of relative peace and prosperity, punctuated by occasional disputes over tribute, trade terms, or the behavior of outsiders. Contemporary Japanese documents and Ainu oral histories both point to tensions arising from attempts by the Matsumae to monopolize trade or impose tribute—disputes that sometimes escalated into skirmishes or the temporary closure of trade routes.

Beneath the surface prosperity, new challenges began to emerge. The growing presence of Japanese settlers in southern Hokkaido brought increased competition for land and resources, leading to gradual shifts in settlement patterns and occasional displacement of Ainu communities. The introduction of foreign diseases, against which the Ainu had little immunity, sometimes swept through villages with devastating effect—a pattern corroborated by sudden drops in population in burial records and oral laments preserved by descendants. Overhunting of fur-bearing animals for trade began to strain the delicate balance with the natural world—a tension evident in both declining animal remains in archaeological layers and in the increasingly prominent role of ecological themes in Ainu oral tradition.

Despite these tensions, the enduring image of this era is one of vitality and achievement. The Ainu carved a space for themselves in the currents of East Asian history—not as passive victims of colonization, but as active participants in a world of trade, diplomacy, and cultural creation. Their festivals lit the winter darkness, their stories preserved the wisdom of generations, and their artisans transformed wood, fiber, and bone into objects of enduring beauty. As the 18th century dawned, the Ainu stood at the height of their power, even as the forces of change gathered on the horizon, poised to challenge the foundations of their civilization.

With the first distant rumblings of imperial ambition from both Japan and Russia, the stage was set for a new and uncertain era. The Ainu, so long the masters of their own world, would soon confront pressures that no ritual or alliance could easily dispel.