In the heart of Japan’s ancient capital, Heijo-kyo, a breathtaking discovery has brought the 8th century vividly back to life. Archaeologists, digging in preparation for a modern apartment complex in Nara Prefecture, stumbled upon the grand remains of what is believed to be the long-lost residence of Prince Toneri (676–735 AD), a towering figure of Japan’s Asuka and early Nara periods. This extraordinary find unveils a forgotten chapter of history, shedding light on the opulent life of a prince whose legacy shaped the cultural and spiritual landscape of Japan.
Heijo-kyo, the vibrant capital of Japan from 710 to 784 AD, was a meticulously planned city, its streets laid out in a precise square grid. As the epicenter of politics, culture, and religion, it housed majestic palaces, temples, and administrative complexes. This urban masterpiece became the blueprint for future Japanese cities, reflecting the sophistication of the Nara period. Among its elite residents was Prince Toneri, son of Emperor Tenmu and Empress Jito, and younger brother of Empress Genmei. Though he never ascended the throne, Toneri’s influence was profound, most notably through his compilation of the Nihon Shoki—Japan’s second-oldest historical text—and his fervent patronage of Buddhism, including the construction of the iconic Yakushi-ji temple.
The discovery, announced by the Nara City Board of Education on April 3, 2025, followed excavations conducted between January and March at a site slated for a new apartment complex. Spanning 370 square meters (3,982.65 square feet), the site revealed three main buildings, constructed using the “hottate-bashira” technique, where massive timber pillars were anchored directly into the ground to support a grand structure. The northernmost building, the largest of the trio, measures an impressive 20 meters (65.61 feet) east to west and over 10 meters (32.8 feet) north to south. Square holes, each 1.5 meters (4.92 feet) wide, were found within, once holding the colossal pillars that upheld this majestic residence.
Adding to the site’s grandeur, archaeologists uncovered baked roof tiles produced in a single kiln, spread across an area equivalent to four “towns”—a traditional land measurement of 130 meters (426.5 feet) per side. This vast expanse, seamlessly integrated across multiple towns, underscores the site’s significance as a unified complex, likely reserved for the highest echelons of society.
Toshihide Omi, chief senior specialist for cultural properties with the Cultural Affairs Agency, emphasized the site’s aristocratic character. The presence of multiple large buildings, enclosed by fencing, points to a private residence rather than an administrative hub. Given its scale and prime location in the heart of Heijo-kyo, researchers strongly believe this was the home of Prince Toneri himself. In the Nara period, land was allocated based on rank: aristocrats of the fifth rank or lower received one town, while high-ranking figures like Prince Nagaya (676–729 AD), a key political player, were granted four. The sheer size of this complex suggests Toneri, a prince of immense influence, commanded a residence befitting his status.
Tragically, this remarkable window into Japan’s past will soon be sealed beneath modern development. With excavations complete, the site will be paved over for the planned apartment complex. According to a report in Asahi, there are no plans to inform future residents of the historical treasures lying beneath their homes. The ancient pillars, tiles, and stories of Prince Toneri’s world will be locked in cement, preserved only in the records of archaeologists and the imaginations of history enthusiasts.
Prince Toneri’s legacy extends far beyond the physical remnants of his residence. His work on the Nihon Shoki chronicled Japan’s early history, blending myth and fact to cement the nation’s cultural identity. His devotion to Buddhism left an indelible mark, with temples like Yakushi-ji standing as testaments to his vision. Now, this stunning discovery in Nara Prefecture breathes new life into his story, reminding us of the grandeur and ambition of Heijo-kyo’s golden age. Though the site may soon vanish beneath modern foundations, the spirit of Prince Toneri’s era endures, whispering tales of a time when emperors, scholars, and visionaries shaped a nation.