Saio

Saio, also spelled Saiō (Japanese: 斎王), is a historical term referring to an unmarried princess of the Japanese imperial family who served as a high priestess at the Ise Grand Shrine, one of Shinto’s most important sacred sites. The Saiō acted as the imperial representative in Shinto rites and ceremonies carried out at Ise, primarily at the Inner Shrine (Naiku). The institution is thought to have originated in the early centuries of Japanese statehood and became more formalized during the Nara and Heian periods.

Selection for the role came from among royal princesses or other high-ranking noblewomen. The Saiō would move to Ise to fulfill religious duties for life or for a specified period. She resided in a designated palace area near the shrine and performed purification rites, offerings, and other sacerdotal tasks to honor Amaterasu, the sun goddess enshrined at Ise. Her presence and rites underscored the close symbolic ties between the imperial house and Shinto religious practice.

The office declined with shifts in political power and religious administration, and by the late medieval period the practice had largely ended. The exact timeline varies among sources, but the practice effectively waned during the 14th century, with later references becoming sporadic. Today the Saiō is mainly of historical and scholarly interest, noted for illustrating the imperial-religious connections of early Japan and the role of women in ritual governance at one of Shinto’s central sanctuaries.