Book of Sui
- Compiled: 636
- Chinese: 隋書 (Suí shū)
The text contains the earliest usages of the word "Liuqiu" (J: Ryûkyû). Though this was taken, within Japan at least, to refer unquestionably to the Ryukyu Islands, all the way up through the 1860s, an 1874 work by the Marquis D'Hervey de Saint-Denys questioned this identification, and sparked a debate as to whether this and other ancient Chinese references to "Liúqiú" in fact referred to Taiwan. The debate heated up only beginning in the 1920s, and was politically charged, as an ancient reference to Taiwan in the Book of Sui would help support notions that Taiwan (now, in the 1920s, an integral part of the Japanese Empire) was originally, fundamentally, part of Japan. Wada Kiyoshi's 1924 essay Ryûkyû Taiwan no meishô ni tsuite ("Regarding the Names Ryukyu and Taiwan") was among the earliest and most impactful works in Japanese to advance Saint-Denys' argument. This debate continued into the 1950s, with Okinawan scholars such as Ifa Fuyû, Higaonna Kanjun, and Majikina Ankô joining in; as early as 1926, Ifa asserted that the Book of Sui was referring to Ryûkyû, not to Taiwan, to which Higaonna responded with arguments that while the first reference to Ryûkyû in the Book referred properly to Ryûkyû, later mentions within the text referred to Taiwan.
- Kreiner, Josef. "Ryukyuan History in Comparative Perspective." in Kreiner (ed.) Ryukyu in World History. Bonn: Biersche Verlagsanstalt, 2001. p3.
- Yokoyama Manabu 横山学, Ryûkyû koku shisetsu torai no kenkyû 琉球国使節渡来の研究, Tokyo: Yoshikawa kôbunkan (1987), 8-11.