What this song renders
Kurikara is one of the most consequential battles of the Genpei War. The Taira had sent a large army north to suppress Yoshinaka’s rising; he met them at the Tonamiyama pass and drew them into the steep ravine of Kurikara at night. The chronicles describe the famous fire-oxen tactic — cattle driven with torches tied to their horns into the front of the Taira encampment — though it appears most prominently in the Heike Monogatari’s literary version. The result, however described, was a complete rout: large parts of the Taira army were pushed off the cliff into the gorge.
Kurikara was the engagement that broke the Taira’s ability to defend Kyoto. Within months Yoshinaka had taken the capital. The Genpei War would not end here, but the Taira loss of strategic momentum did.
The Heike does not name Tomoe at Kurikara. The album places her there because Yoshinaka’s campaign is documented as the context for everything the Heike does say about her, and because Kurikara is the kind of engagement where a warrior the chronicle calls worth a thousand would matter most.
The Battle of Kurikara, the date, the location, the fire-oxen tactic (in literary form), and Yoshinaka’s decisive victory are all documented. Tomoe’s leadership of one of the columns is the song’s extrapolation from her attested presence in his command.