The Japanese punitive expedition to Taiwan in 1874, referred to in Japan as the and in Taiwan and Mainland China as the Mudan incident (), was a punitive expedition launched by the Japanese ostensibly in retaliation for the murder of 54 Ryukyuan sailors by Paiwan aborigines near the southwestern tip of Taiwan in December 1871. In May 1874, the Imperial Japanese Army and Imperial Japanese Navy attacked the indigenous Taiwanese peoples in southern Taiwan and retreated in December after the Qing dynasty agreed to pay an indemnity of 500,000 taels. Some ambiguous wording in the agreed terms were later argued by Japan to be confirmation of Chinese renunciation of suzerainty over the Ryukyu Islands, paving the way for de facto Japanese incorporation of the Ryukyu in 1879.
Background
Mudan incident
In December 1871, a Ryukyuan vessel shipwrecked on the southeastern tip of Taiwan and 54 sailors were killed by aborigines. Four tribute ships were returning to the Ryukyu Islands when they were blown off course on 12 December. Two ships were pushed towards Taiwan. One of them landed on Taiwan's western coast and made it back home with the help of Qing officials. The other one crashed into the eastern coast of southern Taiwan near Bayao Bay. There were 69 passengers and 66 managed to make it to shore. Fifty-four of them were killed by Paiwan while the remaining 12 were rescued by Han Chinese who transferred them to Taiwan Prefecture (modern Tainan). They then made their way to Fujian province in mainland China and from there, the Qing government arranged transport to send them home. They departed in July 1872
This event, known as the Mudan incident, did not immediately cause any concern in Japan. A few officials knew of it by mid-1872 but it was not until April 1874 that it became an international concern. The repatriation procedure in 1872 was by the books and had been a regular affair for several centuries. From the 17th to 19th centuries, the Qing had settled 401 Ryukyuan shipwreck incidents both on the coast of mainland China and Taiwan. The Ryukyu Kingdom did not ask Japanese officials for help regarding the shipwreck. Instead its king, Shō Tai, sent a reward to Chinese officials in Fuzhou for the return of the 12 survivors.
Diplomacy
On 30 August 1872, Sukenori Kabayama, a general of the Imperial Japanese Army, urged the Japanese government to invade Taiwan's tribal areas. In September, Japan dethroned the king of Ryukyu. On 9 October, Kabayama was ordered to conduct a survey in Taiwan. In 1873, Tanemomi Soejima was sent to communicate to the Qing court that if it did not extend its rule to the entirety of Taiwan, punish murderers, pay victims' families' compensation, and refused to talk about the matter, Japan would take care of the matter. The Foreign Minister Sakimitsu Yanagihara believed that the perpetrators of the Mudan incident were "all Taiwan savages beyond Chinese education and law." Japan justified sending an expedition to Taiwan through linguistic interpretation of huawai zhimin (lit. outside the sphere of civilization) to mean not part of China. Chinese diplomat Li Hongzhang rejected the claim that the murder of Ryukyuans had anything to do with Japan once he learned of Japan's aspirations. However, after communications between the Qing and Yanagihara, the Japanese took their explanation to mean that the Qing government had not opposed Japan's claims to sovereignty over the Ryukyu Islands, disclaimed any jurisdiction over Aboriginal Taiwanese, and had indeed consented to Japan's expedition to Taiwan. In the eyes of Japan and the foreign advisor Charles Le Gendre, the aborigines were "savages" who had no sovereign or international status, and therefore their territory was "terra nullius", free to be seized for Japan. The Qing argued that like in many other countries, the administration of the government did not stretch to every part of a country, similar to the Indian territories in the United States or aboriginal territories in Australia and New Zealand, a view Le Gendre also took before his employment by the Japanese.