Cornerstone" may be a superlative: a word perhaps alluding to the paradoxical case of a tiny kingdom of islands in the East China Sea at the forefront of geopolitics.And the key element itself-one of dynastic rule at Shuri on Okinawa Island-was far from rock solid.Since the early seventeenth century to the late nineteenth century, a fluctuating amount of autonomy could be carved out only with an elaborate configuration of respect vis--vis two regional entities: imperial China and feudal Japan.Mamoru Akamine's book highlights the way a Ryukyuan king would receive a patent of investiture from the emperor of China.Vassal status thus conferred entitled the court to conduct trade between entrepts along the Asian sea lanes.Acceptance of credentials at the Ministry of Ritual in Beijing underscores this cultural concomitant: vocal address in official Mandarin language and ceremonial address in exemplary sync with assigned vassal rank.Trade was thus a privilege sustained by tribute-as-obeisance.
Arne Røkkum (Tue,) studied this question.