• Born: c. 1326
  • Died: c. 1354
  • Titles: 中山国王 (J: Chûzan-kokuô, King of Chûzan) (c. 1336-1354)
  • Japanese/Okinawan: 西威 (Seii)

Seii is described in official histories compiled by the Ryûkyû Kingdom as the second king of the Okinawan kingdom of Chûzan. He succeeded his father, Tamagusuku, in 1336, at the age of ten. His reign is characterized by the meddling of his mother in government affairs, and her corruption. The king's mother took advantage of her privileges and position, and severely damaged popular support for her son.

In the wake of Seii's death in or around 1354, the Governor of Urasoe, Satto, seized power for himself. Official histories compiled by 17th-18th century kingdom officials, much like official histories elsewhere in premodern/early modern East Asia, justify and legitimize Satto's succession by characterizing Seii's reign as chaotic, and that of Satto as enlightened and virtuous. The historical truth is thus difficult, if not impossible, to discern.[1]

Preceded by:
Reign as King of Chûzan
c. 1336-1354
Succeeded by:


  • Kerr, George H. (2000). Okinawa: the History of an Island People. (revised ed.) Boston: Tuttle Publishing. p62.
  1. Gregory Smits, Maritime Ryukyu, University of Hawaii Press (2019), 151.