Shukaku Shinnō 守覺親王 (1150–1202) was the second son of Emperor Go-Shirakawa 後白河天皇 (1127–1192) and the great imperial-prince-monk (hosshin’ō 法親王) of late-12th-century Japan. He was tonsured into Shingon at Ninnaji 仁和寺 and became its sixth abbot — the Sixth Omuro 第六御室 — and the principal religious counselor of his father’s cloistered-court Buddhism after Go-Shirakawa’s own tonsure in 1169. Through the era of the Genpei War 源平合戰 (1180–1185) and the establishment of the Kamakura bakufu, Shukaku stood as the most senior religious-political figure of imperial Buddhism, and his many compilations preserve the imperial-house Shingon practice of that pivotal moment.
His scholarly output is exceptional in scope: he compiled and edited at least five major ritual encyclopedias preserved in the Taishō canon, drawing on the transmissions of his teachers and contemporaries: KR6t0194 Sawa-shō (ten fasc., from Kakujō 覺成), KR6t0195 Hishō (eighteen fasc., from Shōken 勝賢), KR6t0196 Ison-shō (two fasc., independent compilation), KR6t0197 Uki (one fasc.), KR6t0198 Saki (one fasc.), KR6t0199 Gyoki (one fasc.), and KR6t0200 Tsuiki (one fasc.). Together these comprise the Hosshōji-no-miya Goshō 法性寺宮御書 — the great imperial-prince-monk’s ritual collection.
In addition to his Shingon scholarship, Shukaku was an accomplished waka poet and patron of the arts; the Senzaishū 千載集 and Shinkokinshū 新古今集 both include his compositions.