Diaoyu Island and its affiliated islands, including Huangwei Islet, Chiwei Islet, Nanxiao Island and Beixiao Island (hereafter referred to as the Diaoyu Islands) have been an integral part of Chinese territory since ancient times. The book Voyage with a Tail Wind (Shun Feng Xiang Song), which appeared in 1403 (the first year of the reign of Emperor Yongle of the Ming Dynasty), recorded the names of islands that Chinese voyagers passed en route from Fujian to Ryukyu such as "Diaoyu Islet" and "Chikan Islet", known today as Diaoyu Island and Chiwei Islet.
The imperial courts of the Ming and Qing dynasties sent imperial title-conferring envoys to the Ryukyu Kingdom 24 times. Records of the Imperial Title-Conferring Envoys to Ryukyu (Shi Liu Qiu Lu), and voluminous materials left by the envoys, have depicted the topography and geography of the Diaoyu Islands in detail and recorded the demarcation line between China and Ryukyu east of Chiwei Islet. In 1534 (the 13th year of the reign of Emperor Jiajing of the Ming Dynasty), Chen Kan, an imperial title-conferring envoy from the Ming court to Ryukyu, set out in Records of the Imperial Title-Conferring Envoys to Ryukyu China's earliest official record of the maritime boundary between China and Ryukyu: "Diaoyu Islet, Huangmao Islet, Chi Islet, so many islands unfold before my eyes Then Kume Mountain comes into sight; that is where the land of Ryukyu begins. The Ryukyuans on my ship are happy and excited, because they know they have finally returned to their homes." The passage indicates that Ryukyuans believed they had arrived at Ryukyu when they saw Kume Mountain (known as Kumejima Island today) after passing Chiyu Islet (known as Chiwei Yu today). This indicates that the Diaoyu islands belong to China, not Ryukyu.
