Radiocarbon Dating of Kohitsugire Calligraphies Attributed to Asukai Masatsune and the Periods of Origin of Genji Monogatari Emaki and Ban-Dainagon Ekotoba

Genji monogatari emaki and Ban-dainagon ekotoba are Japanese national treasures. Although the periods in which they were painted have not been accurately determined, radiocarbon dating cannot be applied to these priceless artifacts because of the destructive nature of 14C dating. In this study, the periods of their origin were determined by 14C dating the kohitsugire calligraphy. Kohitsugire are ancient paper sheets containing graceful calligraphy. They originally were part of ancient manuscripts. Two kohitsugire named Imaki-gire and Kingin-kirihaku-wakanroeishu-gire are written in the same style as Genji monogatari emaki and Ban-dainagon ekotoba. Although Imaki-gire and Kingin-kirihaku-wakanroeishu-gire had been attributed to Asukai Masatsune (AD 1170–1221) on the basis of the kiwamefuda certificates, recent calligraphical and paleographical studies suggest that they are genuine handwritings of Fujiwara no Norinaga (AD 1109–1180?). We applied 14C dating by accelerator mass spectrometry (AMS) to Imaki-gire and Kingin-kirihaku-wakanroeishu-gire. The calibrated 14C ages of both the kohitsugire indicated timing close to the peak of Fujiwara no Norinaga's career as a calligraphist. Based on the associations between the dated texts and the 14C results, it is concluded that the Genji monogatari emaki and Ban-dainagon ekotoba paintings could have been created in the middle of 12th century.