Legitimacy of Kojiki and the Shifting Historical Landscape of Japan’s Oldest Text

Re-examining the Myth of Unbroken Imperial Lineage Through Modern Scholarship

Recently, the historical authenticity of the Kojiki (古事記), Japan’s oldest surviving historical document, has come under renewed scrutiny. This is particularly relevant to ongoing debates about the controversial “Eight Undocumented Monarchs” (欠史八代, Kesshi Hachidai), which directly challenge the traditional Japanese narrative of an unbroken imperial lineage (bansei ikkei, 万世一系).

According to traditional accounts, Japan’s first emperor, Jimmu (神武天皇), ascended the throne in 660 BCE in Kashihara, located in today’s Nara Prefecture. To uphold the legitimacy of the imperial lineage, every subsequent emperor must be historically verified. However, modern historical analysis increasingly questions the existence of the second through ninth emperors listed in ancient chronicles:

• 2nd Emperor Suizei (綏靖天皇)

• 3rd Emperor Annei (安寧天皇)

• 4th Emperor Itoku (懿徳天皇)

• 5th Emperor Kōshō (孝昭天皇)

• 6th Emperor Kōan (孝安天皇)

• 7th Emperor Kōrei (孝霊天皇)

• 8th Emperor Kōgen (孝元天皇)

• 9th Emperor Kaika (開化天皇)

Historians now commonly regard these eight monarchs as later fabrications, added retrospectively to create a seamless historical lineage. In contrast, substantial historical and archaeological evidence supports the existence of the 10th Emperor Sujin (崇神天皇), making him widely accepted as Japan’s earliest verifiable emperor. Numerous historical records and sites in southern Nara Prefecture confirm his reign and significance.

But this leads to a critical question: Is the Kojiki simply a fictional creation of later eras? While some extreme viewpoints argue this, the reality demands more nuanced exploration.

The Kojiki originated as a state-sponsored project under Emperor Tenmu (天武天皇, r. 673–686), following a turbulent period of imperial succession struggles. Remarkably, Emperor Tenmu deliberately chose not to transcribe these histories immediately into writing. Instead, he relied on a single court official, Hieda no Are (稗田阿礼), who memorized the narratives through intense oral repetition.

Following Tenmu’s death, his widow, Empress Jitō (持統天皇, r. 690–697), ascended to the throne. Subsequently, their grandson, Emperor Monmu (文武天皇, r. 697–707), son of a daughter of Emperor Tenji (天智天皇, r. 668–672)—Tenmu’s elder brother—assumed the throne. This period of succession intricacies profoundly shaped the Kojiki’s development.

The true decisive moment arrived under Empress Genmei (元明天皇, r. 707–715). Concerned that the invaluable oral traditions would vanish with Hieda no Are’s death, she commanded courtier Ō no Yasumaro (太安万侶) to transcribe Are’s memorized accounts. This undertaking culminated in 712 CE with the compilation of Kojiki. Simultaneously, Genmei initiated the Nihon Shoki (日本書紀), completed in 720, aligning Japan’s historiography closer to Chinese models. She also commissioned regional officials to produce local records known as Fudoki (風土記), ensuring regional traditions were documented for future generations.

For centuries, the narratives of Kojiki and Nihon Shoki were broadly accepted as historical fact. However, recent scholarly voices call for a critical reassessment of these ancient texts. A prominent figure spearheading this re-evaluation is Professor Sadakazu Fujii (藤井貞和, b. 1942), emeritus professor at the University of Tokyo.

Fujii, whose father studied under eminent ethnologist Shinobu Orikuchi (折口信夫), developed an early expertise in ancient Japanese narratives and Shinto history. Throughout his career, Fujii deeply explored Japan’s literary traditions, particularly focusing on the historical evolution of monogatari (物語, narrative literature).

In 2022, Fujii advanced a groundbreaking hypothesis, arguing that the crucial preface of Kojiki—which attributes its compilation to Hieda no Are and Ō no Yasumaro under imperial orders—was, in fact, a later fabrication. If correct, this revelation would fundamentally undermine the historical credibility of Kojiki, raising profound questions about Japan’s earliest written history.

This discovery holds major implications for Japanese historiography, potentially reshaping the nation’s understanding of its early historical identity. Scholars now face the significant task of reassessing ancient texts not simply as historical records but as complex narratives shaped by political, social, and ideological influences.

Moving forward, we must carefully reconsider how Japan’s early histories were written and understood, mindful of their enduring influence on contemporary national identity and cultural heritage.