The Diaoyu Islands

Location of the Diaoyu Islands (Xinhua photo)

The Diaoyu Islands (钓鱼岛) are an inalienable part of Chinese territory. They are at the frontline of the defense of China's sovereignty.

The Diaoyu Islands – full name Diao Yu Tai Archipelago 钓鱼台群岛) – are referred to as the Senkaku Islands (尖阁列岛/尖閣諸島) by Japan; they consist of Diaoyu Island, Huangwei Island, Chiwei Island, Nanxiao Island, Beixiao Island, Dananxiao Island, Dabeixiao Island and Feilai Island, and cover an area of about 7 km2.

Geographical position: 123°–124°34' E (east longitude) and 25°40'–26° N (north latitude)

Relative position: Due east to Fujian; northeast to Taiwan; 102 nautical miles away from Ji Long and 230 nautical miles away from Naha.

Geological features: The waters of the Diaoyu Islands are situated on a tertiary sedimentary basin, and are rich in oil deposits estimated in 1982 to have potential annual output of 737–1574 billion barrels.

Geographical features: Diaoyu Islands, geographically part of Taiwan Island, are a group of islands standing on the continental shelf, separated from the Ryukyu Islands by a deep underwater trench.

Historical background:

China's earliest record of the Diaoyu Islands can be traced back to the Sui Dynasty, more than 1,000 years ago. At the time, China's Taiwan and the Diaoyu Islands were close to another independent state called Ryukyu (琉球国). And Emperor Yang of the Sui Dynasty (隋炀帝) sent Zhu Kuan (朱宽) as a special emissary to win it over and demand it pledge allegiance to the Sui Court. In the 14th century, Emperor Taizu of the Ming Dynasty (明太祖) was known far and wide for his military prowess. Thus, the King of Ryukyu started to pay tribute to the imperial court officially and Ryukyu became a vassal state of the Ming Dynasty.

The Diaoyu Islands (钓鱼岛)

In 1372, a Chinese named Yang Zai (杨载) landed on the Diaoyu Islands for the first time. There was a detailed record about Diaoyu Islands in the book Sail with the Wind (顺风相送) , a navigational guidebook, which was published during the reign of Emperor Yongle (永乐) of the Ming Dynasty. During that period, people of the Ming Dynasty collected pearls and medicinal ingredients and fished around the Diaoyu Islands under the jurisdiction of Taiwan. This was also clearly recorded in Reports on the Mission to Ryukyu (使琉球录), a book written by Chen Kan (陈侃) in the 11th year of the reign of Emperor Jiaqing (嘉庆) of the Ming Dynasty. In the middle of the Ming Dynasty, some national heroes, such as General Qi Jiguang (戚继光), used the Diaoyu Islands as the strategic line of defense, when they fought against Japanese pirates. In 1602, Japan invaded Ryukyu. From then on, Ryukyu's internal affairs were under the supervision of the Japanese for over 40 years. In 1654, Emperor Kangxi of Qing Dynasty (清康熙帝) bestowed on the King of Ryukyu the title of King Shangzhi (尚质王). Ryukyu was obliged to pay tribute to the imperial court every two years, regarding China as "the Father State" and assuming the reign title of Qing Dynasty. Many maps and nautical charts of the Ming and Qing dynasties clearly marked Diaoyu Islands as part of China's territory.

In 1873, Japanese troops invaded and occupied China's vassal state – Ryukyu Islands, incorporating it into Japan's territory under the name of Okinawa. Although the governor of Ryukyu Islands sent envoys to the capital city of Qing Dynasty to seek reinforcements, the imperial court (1644-1911), corrupt and inept, only lodged "a strong protest" against Japan and left the matter there. As a result, Ryukyu Islands were taken by Japan from then on. In spite of this, Diaoyu Islands remained within the jurisdiction of Taiwan, a province of the Qing Empire. In 1893, the Empress Dowager Cixi (1835-1908) bestowed Diaoyu Islands on Sheng Xuanhuai (盛宣怀1844-1916), who was in charge of the Office of the Imperial Household, to gather medicinal ingredients there.

After the Sino-Japanese War of 1894-1895, the Qing court was forced to sign the Treaty of Shimonoseki with Japan, a treaty of national betrayal and humiliation. This treaty only stipulated in explicit terms that China should cede Taiwan and the Penghu Liedao (the Pescadores) to Japan, without mentioning Diaoyu Islands which were within this sea area. In 1940, the governors of Taiwan and the Ryukyu Islands, which were both under Japan's jurisdiction, contended for jurisdiction of Diaoyu Islands. Later on, the Tokyo Tribunal pronounced that Diaoyu Islands were still under the administration of Taiwan. In 1945, when Japan surrendered to China, the US, Britain, France and other allied countries, it declared the unconditional abolition of all the unequal Sino-Japanese treaties, including the Treaty of Shimonoseki. Consequently, Taiwan and the other archipelagos under its jurisdiction, including the Diaoyu Islands, reverted to China's sovereignty.

According to the Cairo Declaration, the Potsdam Proclamation and other important proclamations of international conferences, Japan's occupation of Diaoyu Islands was a grave breach of international law. The Cairo Declaration, concluded by China, the US and Britain on December 1, 1943, stipulated that "all territories Japan stolen from the Chinese, such as Manchuria, Formosa and the Pascadores, shall be restored to the Republic of China". On July 26, 1945, China, the US and Britain issued the Potsdam Proclamation. (The Soviet Union attended this meeting on August 8.) Article Eight highlighted that "The terms of the Cairo Declaration shall be carried out and Japanese sovereignty shall be limited to the Islands of Honshu, Hokkaido, Kyushu, Shikoku and such minor islands as we determine." On August 15, 1945, the Mikado of Japan accepted the Potsdam Proclamation and surrendered unconditionally.

In the Cold War period, the US, in order to carry out its strategy of containment, put the Diaoyu Islands under its own administration. In June 1971, the US "retroceded" the Diaoyu Islands and Okinawa to Japan. As a result of this so-called "agreement", which was an overt violation of international treaties, Japan took over the Diaoyu Islands the following year. The Chinese government issued a statement immediately, firmly opposing the US collaboration with Japan to list the Diaoyu Islands, a part of China's territory, among "regions to be returned" and pointing out the illegitimacy of such an act.

The Chinese and Japanese governments made a joint declaration in 1972. Article 3 of the said declaration reads: "… the Japanese government fully understands and respects the position taken by the Chinese government and insists on adhering to the position stated in Article 8 of the Potsdam Proclamation."

By going through the relevant provisions of the Convention on the Continental Shelf which came into force in 1964 and the UN Convention on the Law of the Sea adopted in 1982, the Diaoyu Islands and Taiwan Province form part of the same geological structure. The Diaoyu Islands, together with Taiwan Province, Penghu and the Zhoushan Archipelago (舟山群岛) are all located on the natural extension of the same continental shelf, and are separated by a 2,000 feet deep trench from the Ryukyu Islands, which are, at present, under the jurisdiction of the Japanese. According to the internationally recognized principle of the Convention on the Continental Shelf, "sovereignty of the islands located on the same continental shelf belongs to the said country." Since China enjoys the sovereignty of the entire East China Sea (中国东海) continental shelf, hence naturally, China also enjoys sovereignty over the Diaoyu Islands.

So, whether judging from the Possession of Discovery or the "Cairo Declaration" and the "Potsdam Proclamation" as well as the "Convention on the Continental Shelf" and "UN Convention on the Law of the Sea", both of which took effect since the 1960s, China's sovereignty over Diaoyu Islands is generally acknowledged and beyond dispute.

Origin of the disputes:

Until the Sino-Japanese war of 1894-1895, Japan raised no objections to China's sovereignty over Diaoyu Islands. In 1884, a Japanese man by the name of Tatsushiro Koga (古贺辰四郎) who lived in Naha (那霸), landed on Diaoyu Islands for the first time to collect feathers and other items from the sea. Later, he applied to the prefect of Okinawa Prefecture to develop the Diaoyu Islands but his application was turned down. After 1885, the prefect of Okinawa submitted many written requests to the Japanese government, asking for approval of his jurisdiction over Diaoyu Island, Huangwei Island and Chiwei Island. Considering the Chinese Qing government's claim over these islands, the Japanese government made no reply. But after the Sino-Japanese war of 1894-1895, Japan forcibly took Taiwan and its subsidiary islands by compelling the Qing government to sign the Treaty of Shimonoseki (马关条约), under which China ceded the whole island of Taiwan and its surrounding islands including the Penghu Islands to Japan. Only since then has Japan had its own name for the area where the Diaoyu islands are located. Before that, Japanese maps marked the islands by their Chinese names.

After Japan's defeat at the end of World War II, Taiwan was returned to China, but its subsidiary islands, such as Diaoyu Islands, were placed under the trusteeship of the United States without concerned parties being consulted.

In the late 1960s, after a committee member of the United Nations announced that the vicinity of the islands was possibly rich in oil and natural gas, Japan immediately took unilateral actions. First it allowed many petroleum companies to move to the islands to carry out surveys. Then it sent patrol boats to destroy, without authorization, the original signpost indicating China's sovereignty over the islands, and replaced the signpost with a boundary marker, stating that the islands are part of the Okinawa Prefecture. It even gave Japanese names to the eight adjacent islands in the Diao Yu Tai Archipelago.

In 1971, when signing the treaty for the return of Okinawa, the US and Japan made a private agreement to include the Diaoyu Islands into the territory to be returned to Japan. This transaction met with strong objections from the Chinese government. In 1972, during the China-Japan negotiations to resume diplomatic relations, both countries agreed, considering their overall amicable bilateral ties, to shelve the dispute over the ownership of Diaoyu Islands. The issue was left to be resolved later when conditions permitted. However, in 1978, during the negotiations between China and Japan for the signing of China-Japan peace treaty, some Japanese Diet members with hostile attitudes towards China demanded that China acknowledge Japan's sovereign rights over the Diaoyu Islands. The Japanese government acceding to the demands of the right-wingers, sent patrol vessels and aircraft to keep watch on Chinese fishermen operating around the Diaoyus. In May the following year, the Japanese government employed patrol boats to ferry personnel and equipment to the Diaoyu Islands, to build a helicopter landing pad, and dispatched a survey team and a surveying vessel to the islands.

Since the 1990s, based on a false judgment about world situation and about the shift in power between nations, Japan, once again, began to lay its hands on the Diaoyu Islands. In October 1990, Japanese right-wingers, backed by their government, erected a beacon tower on one of the islands. Japan also prevented some Taiwan fishermen from approaching Diaoyu Islands by deploying 12 boats and two helicopters. On July 14, 1996, Japanese right-wingers built another beacon tower on a small islet of Beixiao Island in an attempt to add the small island to their nautical chart so they might win international recognition through cheating. On August 18 of the same year, Japanese right-wingers put up on the Diaoyu Islands their "Sun Flag" (Hinomaru) and some wooden tablets bearing the names of executed war criminals. What merits public attention is the fact that the Japanese right-wingers' illegal acts on Diaoyu Islands were acquiesced in and supported by their government. Some Japanese politicians even overtly voiced their support for such acts, claiming that the "Senkaku Islands (what the Japanese call China's "Diaoyu Islands) are Japan's territory" and that "the Japan Coast Guard (海上保安厅) shall repel intruders by force at any time".

Movement to Protect the Diaoyu Islands

On April 2 1947, the United Nations entrusted the sovereignty of Okinawa Islands (冲绳群岛) to the US in an Agreement on Trusteeship of the Archipelago Entrusted by Japan. (关于托管前日本委任统治岛屿的协定). The Diaoyu Islands, which were small, barren and deserted islands then, were used by American military forces as a missile testing ground.

In 1970, American military forces transferred the executive power on the Okinawa Islands to Japan, including the Diaoyu Islands along with them. This ignoring of Chinese sovereignty stirred the fury of Chinese all over the world. Since January 1971, the protection of the Diaoyu Islands has developed into a movement involving all Chinese worldwide. It was first started by some 2,500 Chinese students in the US who gathered in front of UN headquarters claiming Chinese sovereignty over the Diaoyus. This was supported by all Chinese from every corner of the world. Because of this, the American government said that it had only transferred the power of jurisdiction to Japan not sovereignty.

Despite the anger of all Chinese at home and overseas, the Taiwan authorities that, at the time, held China's permanent seat on the UN Security Council took no action, apart from declaring its "resentment". Meanwhile the People's Republic of China was embroiled in the "Cultural Revolution" (1966-76) and could neither take charge of the islands nor refer the matter to the UN or to the International Court for deliberation. All these circumstances left Japan with an opportunity.

During the normalization of China-Japan diplomatic relations in 1972 and the establishment of peaceful and friendly Sino-Japanese relations in 1978, China agreed that both sides should seek common ground while putting aside differences, and that the Diaoyu Islands issue could be solved at a later date. In addition China gave up the right to ask for war indemnities, in view of maintaining China-Japan relations. But Japan Youth Association (日本青年社), the right wingers in Japan, erected a light house on Diaoyu Island that year. Chinese fishermen were also often harassed by Japan Coast Guard vessels and aircraft.

From May 8 to June 8, 1979, Japan built a temporary helicopter pad and sent an investigation team and a survey vessel to the area around the Diaoyu Islands. In 1989, Japanese gunboats went on patrol, speeding in crazy circles trying to drive Chinese fishermen away, eliciting strong protests from Chinese all over the world. In 1990, the Japan Coast Guard announced that it recognized the light house built by Japan Youth Association as an official navigation marker, stirring up a further wave of protest to protect the Diaoyu Islands. The Chinese government protested officially and the lighthouse issue was shelved once again.

In September 1996, people in Hong Kong started a movement to protect the Diaoyu Islands against the illegal construction of a light house by Japanese right wingers. On September 26 , a young man from Hong Kong by the name of David Chan (陈毓祥) went to Diaoyu Islands on a rented boat named HKS Bao-Diao (保钓号), flying the national flag of China, in an attempt to claim Chinese sovereignty over the Diaoyu Islands. His boat was harassed by the Japanese and Chan and the rest of the crew jumped into the sea in protest. All the others were saved except him.

Corroborative evidence: History, geography and international law

The Diaoyu Islands are an inalienable part of the sacred territory of China. This can be proved by evidence drawn from history, geography and international law.

Historical evidences: Diaoyu Islands were discovered by China 400 years earlier than by Japan

On maps released by Japan before 1895, Diaoyu Islands were not counted as part of Ryukyu Islands. A Complete Map of the Three Provinces of Ryukyu and Thirty Six Islands by Hayashi Shihei (林子平) clearly indicated that the Diaoyu Islands belonged to China, i.e. the Chinese discovered Diaoyu Islands 400 years earlier than the Japanese did.

In addition, the Empress Dowager Tsu-hsi issued an imperial edict in 1893 awarding the Diaoyu Islands to Sheng Hsuan-huai. Sheng Ch'eng-nan (盛承南), a clan member of Sheng Huan-huai's grandchild generation, frequently visited his clan property－the Diaoyu Islands, for Cistanche Salsa and other medicinal herbs ever since he migrated to Taiwan from Jiangsu Province. In Taipei's Greater China Evening News (Sep. 9, 1970), he wrote an article entitled "My Days on the Diaoyu Islands Picking Medicinal Herbs".

There is sufficient historical evidence to prove that Diaoyu Islands are not terra nullius (无主地) but belong to China. They do not belong to Japan, nor are they geologically or geographically connected to the Ryukyu Islands. It was a shameless and peremptory act of robbery on the part of Japan to invade China in an attempt to usurp the sovereignty over Diaoyu Islands.

Geological information: Diaoyu Islands are located in the Taiwan Ocean Basin

Geologically, Diaoyu Islands are located in the vicinity of the Taiwan Ocean Basin on the edge of the East China Seabed. More specifically, the islands are located on the fringe of the continental shelf upon which rest the two Chinese provinces of Fujian and Zhejiang. These islands are natural extensions of the land mass extending from the Chinese mainland and Taiwan Island into the ocean, with the seabed in this region being less than 200 meters in depth. There is a dip in the seabed about 10 nautical miles south of Diaoyu Islands, where the seabed is more than 1,000 feet deep. Geologists refer to this as the "Ryukyu Trough" (琉球海槽). As there are no continental shelves in this trough, in the geographical sense, the Diaoyu Islands are therefore not connected to the Ryukyu Islands and cannot be considered to be part of the natural extension of Japan's Ryukyu territory.

In fact, over the past century, Taiwanese fishermen often operated in the waters around the Diaoyu Islands. When the fishermen encountered thunder storms, they would seek shelter in the 1,500-meter-wide strait between the Diaoyu and Nanxiao Islands. On the other hand, Japanese fishermen were rarely spotted in the area over the past decade. The main reasons for this are simply the prevalent Northeast and Southwest monsoons in the East China Sea throughout the year as well as the Japan Current (黑潮/Kurushio) which flows northeast from Taiwan. As Ryukyu fishermen were unlikely to sail at right angles into the prevailing wind to reach the Diaoyu Islands, this explains why Taiwanese fishermen never encountered any Ryukyu natives.

International Law: China's legal recourse

Japan did not fulfill the condition of "occupation"

The main reason behind Japan's claim to sovereignty over Diaoyu Island is the alleged discovery of Diaoyu Island in 1884 by Tatsushiro Koga, who set up a wooden fish sculpting plant (木头鱼厂) on the island and also collected specimens of bird feathers and feces there. Japan claims that Ryukyu fishermen had long been fishing in the neighbourhood of the Diaoyus.

The significance of this is claims the islands were discovered by the Japanese and that the Japanese were the first to land on, occupy, and use the islands. If this were true, based on international law, Japan would have to satisfy the condition of "occupation" and establish its right to claim sovereignty over the islands. But in August 1970, Koga's son refuted this, saying that his father did not discover the island although he landed on it; and that there were others who had already done so before his father.

The earliest mention of the islands in China's historical records date back to 1403 in the nautical charts of a book entitled Sail with the Wind. In other words, China discovered the islands at least 400 years earlier than Japan.

The Diaoyu Islands are not part of the Ryukyu Islands.

Moreover, in international law, if a party is to take possession of a terra nullius upon discovering it, then that party must be a country or have been entrusted by a country the right to possess it. However, when Koga applied to Japan's Ministry of Internal Affairs and Communication (内政部) to lease the Diaoyu Island, his application was turned down by the Japanese government on the grounds that "the island did not belong to Japan". Also, when then Japanese-occupied Taiwan — "Taihoku Prefecture (Taipei Prefecture) " (台北州) sued the Okinawa (Ryukyu) Prefecture in 1941 in order to retain its fishing grounds around the islands, the courts in Tokyo ruled in 1944 that the islands were under Taiwan's administration.

Hence, when China ceded Taiwan to Japan in 1895 after the first Sino-Japanese War, it also ceded the Diaoyu Islands since the islands were part of Taiwan. This was so, despite the fact that Japan had already taken over Ryukyu at the time. The following year, the Japanese government approved Koga's application and also listed Diaoyu Islands as part of Japan's territory. But it was pointed out in the Declaration issued during the Cairo conference involving China, the US and Britain in 1943 [sic] (Declaration of Cairo) that "all territories taken from China by Japan are to be restored". The clause undoubtedly also included the Diaoyu Islands.

In addition, Clause 1 of Article 76 of Part IV of the UN Law of the Seas Convention (1982) stipulates that "the continental shelf of a coastal State comprises the seabed and subsoil of the submarine areas that extend beyond its territorial sea throughout the natural prolongation of its land territory to the outer edge of the continental margin, or to a distance of 200 nautical miles from the baselines from which the breadth of the territorial sea is measured where the outer edge of the continental margin does not extend up to that distance." In other words, the Diaoyu Islands are part of the natural extensions of China's land territory. Without a doubt, they come under China's full sovereignty.

US and Japan cannot do an under-the-table deal on the islands

One of the main arguments Japan cites in its claim over the Diaoyu Islands is largely based on the US-Japan Peace Treaty (美日和约) signed in San Francisco, that is, the Ryukyu Islands were annexed from Japan when the Treaty went into force. The US State Department issued a statement based on this Treaty and the Reversion Agreement between the US and Japan in relation to the Amami Islands (有关奄美诸岛的日美协定), in which Clause 1 of Article 27 "Geography of Ryukyu" claimed that Diaoyu Islands lie within the geographical vicinity of the Ryukyu Islands. Hence, the US had, based on this argument, returned the Diaoyu Islands to Japan in 1972. However, Japan's claim had completely violated one of the basic principles of international law, since the Vienna Convention on the Law of Treaties states that "a treaty does not create either obligations or rights for a third State without its consent." (Section 4 Treaties and Third States Article 34 General rule regarding third States Clause), hence the territorial sovereignty of a State may not, through treaties agreed between third States, be expropriated or changed. No individual or country may transfer rights that he or the country does not possess to another party. This is a basic principle in private law as well as international law. Although the islands were classified as part of the Ryukyu Islands under the above-mentioned Treaty and Agreement, and were administered by the US, China's sovereignty of the islands remained unaffected. Thus, the third reason cited by Japan in its claim over Diaoyu Islands is untenable according to international law.

Geographical information: origin of the Diaoyu Islands

The Bohai Sea (渤海) and the Yellow Sea (黄海) are shallow seas on China's continental shelf. The southern part of the Yellow Sea is connected to the East China Sea continental shelf. The Okinawa Trough, a deep oceanic trough, lies to the east of the East China Sea. It is 1,000 kilometres long from south to north, and 150 kilometres wide from east to west, and its deepest spot is over 2,700 metres. Stretching from the East China Sea continental shelf to the Okinawa Trough, the vertical height of the continental slope of the East China Sea reaches 2,500 metres. The altitude difference amounts to 2,500 metres.

The East China Sea continental shelf was once a large basin with a depth of 4,000 meters, the edge of which was a chain of mountains on the ocean floor. This chain of mountains blocked sand and clay washed down by the rivers from Chinese mainland, transforming the basin into a shallow sea. The other side of the mountain chain facing the sea was the Okinawa Trough. With the opening up of the seabed, volcanic substances erupted from underground, causing the sea trough fissure to expand further.

There is adequate historical proof that the islands and islets lying on the rim of the East China Sea continental shelf, including the Diaoyu Islands, have been Chinese territories since ancient times. Geographically, they are an extension of the eastern mountain chain of Taiwan. These islands and islets blocked the sand, clay and organic substances washed down by the Yellow River and the Yangtze River, forming an accumulated layer of 4,000 metres rich in oil and natural gas. If the rivers from Chinese mainland had not provided sand or clay to the East China Sea, it would be a basin several thousand meters deep filled with seawater, like the Okinawa Trough. Therefore, from the perspective of the natural evolution of the seabed, the East China Sea continental shelf and the slope are the result of the natural extension of the land and mountain ranges in eastern China, made up of material carried from the Chinese land mass. The Okinawa Trough is a natural divider that separates the continental shelf and slope on the Chinese coast from the Ryukyu Islands, into two completely different oceanic areas.

Historical documents relevant to the Diaoyu Islands

Many historical records show that the Diaoyu Islands belonged to China in the Ming and Ch'ing Dynasties. One or two examples will suffice.

In 1534 during the 13th year of Ming Dynasty Emperor Chia-ching's reign, the imperial envoy to Ryukyu, Ch'en K'an (陈侃), wrote a book, titled Reports on the Mission to Ryukyu (使琉球录), Part of his voyage was recorded as follows,

"On the 10th day, the strong southerly wind pushed the ship forward with lightning speed and we passed by Pingjia Mountain (平嘉山), Diaoyu Island (钓鱼屿), Huangmao Island (黄毛屿) and Chi Island (赤屿). One day and one night's voyage equals that of three days. The foreigners' boats were so small that they were lagging far behind. At sunset of the 11th day, we saw the Gumi Mountain which belongs to Ryukyu. The foreigners all beat drums and danced in the boats to express their joy upon arriving home."

The above-mentioned "Diaoyu Island, Huangmao Island and Chi Island" are today's Diaoyu Island, Huangwei Island (黄尾屿) and Chiwei Island (赤尾屿). Setting off from Fuzhou, Chen K'an and his party passed by the navigation marks, which were Diaoyu Island, Huangwei Island and Chiwei Island. Then they sailed into the Ryukyu waters, as they saw Kume Mountain (姑米山、古米山、久米山) that belonged to Ryukyu. It is clearly said in the account that both Chen Kan and the foreigners from Ryukyu recognized the Kume Mountain, marking their arrival at Ryukyu. Therefore, it's clear that the Diaoyu Islands did not belong to Ryukyu.

In 1722 during the 61st year of Emperor K'ang-hsi's reign in the Ch'ing Dynasty, Hsu Pao-kuang (徐葆光), deputy emissary to Ryukyu, also wrote a book entitled Records of Messages from Chong-shan (中山传信录), which highlighted that "Ryukyu, in the sea, stands opposite to Zhejiang and Fujian provinces". It also indicated that Kume Mountain garrisoned the strategic pass on the southwestern border of Ryukyu. That is to say, the boundary between China and Ryukyu was between Chiwei Island and Kume Mountain.

Geographical environs as proofs

Accounts of a "trench" or "dark current" are often found in the records of imperial envoys to Ryukyu, for example, in Report on the Mission to Ryukyu (使琉球录) by Hsia Tsi-yang (夏子阳) in the 34th year of Emperor Wan Li's reign of the Ming Dynasty, in Collection of Notes in Ryukyu (使琉球杂录) by Wang Chi (汪楫) in the 22nd year of the Ch'ing Dynasty Emperor K'ang-hsi's reign, in Records of Messages from Chong-shan by Hsu Pao-kuang, and "Survey of Ryukyu" (琉球国志略) by Chou Huang (周煌) in the 21st year of Ch'ing Dynasty Emperor Ch'ien Long's reign, in A Sequel to Survey of Ryukyu (续琉球国志略) by Ch'i K'un (齐鲲) in the 13th year of Ch'ing Dynasty Emperor Chia-ch'ing's reign. It is recorded that whenever the accredited fleet to Ryukyu passed by the "trench", it was supposed to offer sacrifices to the Ocean God by throwing pigs, sheep and rice gruel into the sea, burning paper vessels and beating drums. The "trench" was the Ryukyu boundary.

2,000 meters deep, the Ryukyu Trench is located between the Ryukyu Islands and the Diaoyu Islands; it is linked to the Japan Trench in the northeast and the Mariana Trench in the southwest. Geographically, the Ryukyu Trench effectively separates the Ryukyu Islands from China's continental shelf. Diaoyu Island, the Huangwei Island and the Chiwei Island are, together with Taiwan Island, located in an area where the water is only 200 metres deep on the continental shelf. The water surface between the shelf and the Ryukyu Trench appears as a wide band of darker water — this is the Japan Current — a phenomenon similar to what imperial envoys recorded in the past as "passing from dark-blue waters into black waters".

What merits our attention is that the trench was referred to as the boundary between China and other countries in Collection of Notes in Ryukyu by Wang Ji. Testimony can also be found in the Survey of Ryukyu by Chou Huang, in which Chou described the "black water trench" (黑水沟) as a "border of the waters around the Fujian Province with other territories". It is clear then that China by the Ch'ing Dynasty at the latest, already regarded the Ryukyu Trench as the border of the waters around the Fujian Province. Naturally, all the waters and the islands stretching from Chiwei Island to Fujian Province belonged to the Ch'ing Government and were marked as part of its territory on Ch'ing Dynasty maps.

Japanese historical maps also depict the Diaoyu Islands as part of Chinese territory

In 1785, An Illustrated General Survey of Three Countries (三国通览图说or Sanggoku tsuran zusetsu) written by Hayashi Shihei, a prestigious scholar, was published in Japan. The book has five maps, one each for Chosŏn (朝鲜), the Ryukyu Islands, and Ogasawara Island (小笠原岛), and two for the Emishi region (虾夷), i.e. present-day Hokkaido Island. The author explained in the preface of the book, regarding these nautical charts, that "in writing this book, I do not venture to talk about economics, nor show off my knowledge in geography. I merely want to provide warriors with some information on the geographical situation of the three adjacent countries. Though this information seems to be redundant to the martial arts, I personally believe that it nevertheless holds profound implications for the martial arts."

The maps in the book were of meticulous workmanship and, similar to present-day cartographic practices, each region on the maps were demarcated with a different color. Of these, on the "Complete Map of the Ryukyu State", the area belonging to Ryukyu was colored orange, the neighboring area belonging to Japan pale green, and that belonging to China pink. With these different colored zones, the territories' demarcations were, naturally, easy to decipher. And on this map the locations of Diaoyu, Huangwei and Chiwei Islands are marked, and the three islands are the same pink color as China's Fujian and Zhejiang Provinces. On the other hand, Kume Mountain was assigned the same orange color as the Ryukyu territory.

It should be pointed out that An Illustrated General Survey of Three Countries is no ordinary book in Japan. It is deposited in the Cabinet Library (内阁文库), the Court Library (宫内厅书陵部), and libraries of several Japanese universities, including Tokyo University (东京大学), Kyoto University (京都大学) and Waseda University (早稻田大学), as well as other famous libraries.

Of the five maps, the Map of the Ryukyu Kingdom has not only been frequently cited by scholars, but also displayed as a map of historical significance at every exhibition about the history and culture of Okinawa and the Ryukyu Islands.

China released standard names for Diaoyu Island and its affiliated isles

China released standard names and descriptions of the Diaoyu Island (钓鱼岛) and its affiliated isles on March 3, 2012, according to sources with the State Oceanic Administration (SOA).

The island is named as "Diaoyu Island", with its Chinese pronunciation reading "Diao yu Dao". It is described as an island "about 356 kilometers from the city of Wenzhou, 385 kilometers from the city of Fuzhou and 190 kilometers from the city of Keelung."

China has also released names of Diaoyu's 70 affiliated islands, the names in pinyin and description of locations.

The Diaoyu Island and other related isles have been part of inherent Chinese territory since ancient times, and China has indisputable sovereignty over them, said Hong Lei, spokesman of the Chinese Ministry of Foreign Affairs, in a written statement.

"I would like to reiterate that any unilateral action taken by the Japanese side about the Diaoyu Island and its affiliated isles is illegal and invalid," Hong said, "No matter what names Japan has given to the isles affiliated to the Diaoyu Island, it will not change the fact that these islands belong to China".

The spokesperson suggested those who want to know the Diaoyu Islands' standard names should visit websites of the State Council, the SOA and the Ministry of Civil Affairs.

Table: Standard names and descriptions of the Diaoyu Island and its affiliated isles

No.	Standard names	Pinyin	Location descriptions
1	钓鱼岛	Diàoyú Dǎo	距温州市约356千米、福州市约385千米、基隆市约190千米 About 356 km from Wenzhou, 385 km from Fuzhou and 190 km from Keelung
2	龙头鱼岛	Lóngtóuyú Dǎo	位于钓鱼岛东北 Northeast of Diaoyu Island
3	鲳鱼岛	Chāngyú Dǎo	位于钓鱼岛西南 Southwest of Diaoyu Island
4	大黄鱼岛	Dàhuángyú Dǎo	位于钓鱼岛南 South of Diaoyu Island
5	小黄鱼岛	Xiǎohuángyú Dǎo	位于钓鱼岛南 South of Diaoyu Island
6	金钱鱼岛	Jīnqiányú Dǎo	位于钓鱼岛东南 Southeast of Diaoyu Island
7	金钱鱼西岛	Jīnqiányúxī Dǎo	位于钓鱼岛东南 Southeast of Diaoyu Island
8	梅童鱼岛	Méitóngyú Dǎo	位于钓鱼岛东南 Southeast of Diaoyu Island
9	梅童鱼东岛	Méitóngyúdōng Dǎo	位于钓鱼岛东南 Southeast of Diaoyu Island
10	梅童鱼西岛	Méitóngyúxī Dǎo	位于钓鱼岛东南 Southeast of Diaoyu Island
11	龙王鲷岛	Lóngwángdiāo Dǎo	位于钓鱼岛东南 Southeast of Diaoyu Island
12	龙王鲷西岛	Lóngwángdiāoxī Dǎo	位于钓鱼岛东南 Southeast of Diaoyu Island
13	龙王鲷东岛	Lóngwángdiāodōng Dǎo	位于钓鱼岛东南 Southeast of Diaoyu Island
14	龙王鲷南岛	Lóngwángdiāonán Dǎo	位于钓鱼岛东南 Southeast of Diaoyu Island
15	黄姑鱼岛	Huánggūyú Dǎo	位于钓鱼岛东南 Southeast of Diaoyu Island
16	黄尾屿	Huángwěi Yǔ	位于钓鱼岛东北约27千米处 About 27 km northeast of Diaoyu Island
17	海豚岛	Hǎitún Dǎo	位于黄尾屿西北 Northwest of Huangwei Islet
18	大珠岛	Dàzhū Dǎo	位于黄尾屿西 West of Huangwei Islet
19	小珠岛	Xiǎozhū Dǎo	位于黄尾屿西 West of Huangwei Islet
20	上虎牙岛	Shànghǔyá Dǎo	位于黄尾屿北 North of Huangwei Islet
21	下虎牙岛	Xiàhǔyá Dǎo	位于黄尾屿北 North of Huangwei Islet
22	西牛角岛	Xīniújiǎo Dǎo	位于黄尾屿东北 Northeast of Huangwei Islet
23	东牛角岛	Dōngniújiǎo Dǎo	位于黄尾屿东北 Northeast of Huangwei Islet
24	黄牛岛	Huángniú Dǎo	位于黄尾屿东北 Northeast of Huangwei Islet
25	牛尾岛	Niúwěi Dǎo	位于黄尾屿东北 Northeast of Huangwei Islet
26	牛蹄岛	Niútí Dǎo	位于黄尾屿东北 Northeast of Huangwei Islet
27	小龙岛	Xiǎolóng Dǎo	位于黄尾屿西 West of Huangwei Islet
28	大雁岛	Dàyàn Dǎo	位于黄尾屿西 West of Huangwei Islet
29	燕子岛	Yànzi Dǎo	位于黄尾屿西 West of Huangwei Islet
30	刺猬岛	Cìwèi Dǎo	位于黄尾屿西南 Southwest of Huangwei Islet
31	卧蚕岛	Wòcán Dǎo	位于黄尾屿西南 Southwest of Huangwei Islet
32	大金龟子岛	Dàjīngūizǐ Dǎo	位于黄尾屿西南 Southwest of Huangwei Islet
33	小金龟子岛	Xiǎojīngūizǐ Dǎo	位于黄尾屿西南 Southwest of Huangwei Islet
34	海龟岛	Hǎigūi Dǎo	位于黄尾屿西南 Southwest of Huangwei Islet
35	海星岛	Hǎixīng Dǎo	位于黄尾屿东 East of Huangwei Islet
36	海贝岛	Hǎibèi Dǎo	位于黄尾屿东南 Southeast of Huangwei Islet
37	赤尾屿	Chìwěi Yǔ	位于钓鱼岛东约110千米处 About 110 km east of Diaoyu Island
38	赤背北岛	Chìbèiběi Dǎo	位于赤尾屿北 North of Chiwei Islet
39	赤背东岛	Chìbèidōng Dǎo	位于赤尾屿北 North of Chiwei Islet
40	赤背西岛	Chìbèixī Dǎo	位于赤尾屿北 North of Chiwei Islet
41	赤背南岛	Chìbèinán Dǎo	位于赤尾屿北 North of Chiwei Islet
42	小赤尾岛	Xiǎochìwěi Dǎo	位于赤尾屿西 West of Chiwei Islet
43	赤头岛	Chìtóu Dǎo	位于赤尾屿西 West of Chiwei Islet
44	赤冠岛	Chìguàn Dǎo	位于赤尾屿西 West of Chiwei Islet
45	赤鼻岛	Chìbí Dǎo	位于赤尾屿西 West of Chiwei Islet
46	赤嘴岛	Chìzuǐ Dǎo	位于赤尾屿西 West of Chiwei Islet
47	望赤岛	Wàngchì Dǎo	位于赤尾屿西南 Southwest of Chiwei Islet
48	北小岛	Běixiǎo Dǎo	位于钓鱼岛以东约5千米处 About 5 km east of Diaoyu Island
49	鸟巢岛	Niǎocháo Dǎo	位于北小岛东 East of Beixiao Islet
50	鸟卵岛	Niǎoluǎn Dǎo	位于北小岛东 East of Beixiao Islet
51	小鸟岛	Xiǎoniǎo Dǎo	位于北小岛东南 Southeast of Beixiao Islet
52	南小岛	Nánxiǎo Dǎo	位于钓鱼岛东南约5.5千米处 About 5.5 km southeast of Beixiao Islet
53	龙门北岛	Lóngménběi Dǎo	位于南小岛西北 Northwest of Nanxiao Islet
54	龙门岛	Lóngmén Dǎo	位于南小岛西北 Northwest of Nanxiao Islet
55	龙门南岛	Lóngménnán Dǎo	位于南小岛西北 Northwest of Nanxiao Islet
56	卧龙岛	Wòlóng Dǎo	位于南小岛西北 Northwest of Nanxiao Islet
57	卧龙西岛	Wòlóngxī Dǎo	位于南小岛西北 Northwest of Nanxiao Islet
58	飞龙北岛	Fēilóngběi Dǎo	位于南小岛东南 Southeast of Nanxiao Islet
59	飞龙岛	Fēilóng Dǎo	位于南小岛东南 Southeast of Nanxiao Islet
60	龙珠岛	Lóngzhū Dǎo	位于南小岛东南 Southeast of Nanxiao Islet
61	飞龙南岛	Fēilóngnán Dǎo	位于南小岛东南 Southeast of Nanxiao Islet
62	长龙岛	Chánglóng Dǎo	位于南小岛东南 Southeast of Nanxiao Islet
63	金龙岛	Jīnlóng Dǎo	位于南小岛东南 Southeast of Nanxiao Islet
64	北屿	Běi Yǔ	位于钓鱼岛东北约6千米处 About 6 km northeast of Diaoyu Island
65	北屿仔岛	Běiyǔzǎi Dǎo	位于北屿南 South of Bei Islet
66	小元宝岛	Xiǎoyuánbǎo Dǎo	位于北屿西南 Southwest of Bei Islet
67	飞云岛	Fēiyún Dǎo	位于北屿西南 Southwest of Bei Islet
68	元宝岛	Yuánbǎo Dǎo	位于北屿西南 Southwest of Bei Islet
69	南屿	Nán Yǔ	位于钓鱼岛东北约7.4千米处 About 7.4 km northeast of Diaoyu Island
70	飞屿	Fēi Yǔ	位于钓鱼岛东南 Southeast of Diaoyu Island
71	飞仔岛	Fēizǎi Dǎo	位于钓鱼岛东南 Southeast of Diaoyu Island

Source: www.soa.gov.cn