Japan incorporated the Senkaku Islands in 1895, declaring the uninhabited islets in the East China Sea to be “terra nullius,” or land belonging to no one, by international law and with no traces of Chinese control found.
But if the islands are actually owned by China, as Beijing has repeatedly claimed, Japan’s claim could be seriously undermined. So what do historians think about the issue?
Chinese scholars have argued that China recognized the islands as the Diaoyu and used them as part of their “sea defense areas” near Fujian Province as early as the 16th century. A map in a book compiled by Gen. Hu Zongxian in 1561 seems to corroborate this claim.
The map depicts the islands, labeled with their ancient Chinese names, together with many other islands off Fujian, according to the late historian Kiyoshi Inoue of Kyoto University, who thought the Senkakus belonged to China.
But a majority of Japanese historians say the fact that the islets are on a defense map is not evidence that China either regarded or effectively controlled them as its territory.
Another researcher, Shigeyoshi Ozaki, says that Hu, who often clashed with pirates, was gathering information about pirate routes in general and merely put the islets on there as a landmark.
In a 1972 article, Ozaki said two official record books compiled by local Chinese governments in the area did not count the islands as part of their administrative districts. The books are the “Luoyuan Xianzhi” from 1614 and “Ningde Xianzhi” from 1718.
Other ancient documents that Chinese scholars like to refer to are the travel records left by the Chinese delegates to Okinawa, then known as the Ryukyu Kingdom, between the 16th and 19th centuries.
Although many of the documents used to support each side’s claim are disputed, one that the Chinese experts as well as Inoue often referred to is the logbook from a 1683 trip in which the Chinese delegate wrote of a “trench” between the Senkaku and Ryukyu islands that was called the “border of the inside and outside.”
The Chinese experts and Inoue argued that this entry shows the Senkakus were considered Chinese territory.
Japanese experts disagree. The record shows that the Chinese delegate himself didn’t know the meaning of a trench and had to ask one of the crew to explain it. One crew member told him that the trench was “the border of the inside and outside” without elaborating or mentioning anything about a territorial border.
Nobuo Harada, a Japanese doctor who translated all the records of the journey into Japanese, said the crew merely considered the trench to be a dangerous spot in the ocean.
According to the 1683 journal entry, the wind and the waves got rough at the trench and the crew began a ritual ceremony to calm the ocean.