Ryûkyû was the only kingdom to receive such missions. The investiture of the kings of other tributary nations, such as Korea and Vietnam, was conducted within China, with royal ambassadors being granted the investiture by proxy, on behalf of their king. | Ryûkyû was the only kingdom to receive such missions. The investiture of the kings of other tributary nations, such as Korea and Vietnam, was conducted within China, with royal ambassadors being granted the investiture by proxy, on behalf of their king. |