– the eastern mountainous zone, where since the 17th century there were restrictions on Chinese migration (the so-called fenshanming – a decree on the closure of the mountains). There was no Chinese administration there, and the local population (Shenfan or Gaoshan – "highlanders") was ruled by elders.

Meanwhile, in Japan, public discontent was growing fuelled by political crisis, unpopular reforms and the outbreak of the Saga uprising.

Encouraged by the Americans, the Japanese government decided to use the recent incidents as an excuse to relieve social tension within the country and carry out a punitive expedition.

In April 1874, the Imperial Adviser Okumu Shigenobu, was appointed head of the Taiwan appanage office, and Lieutenant General Tsugumichi Saigo was appointed the commander of the troops of this office. In addition to the ground forces, impressive naval forces were also involved, including the armoured corvette Ryujo, built in England not long before these events. But at the last moment, the government halted preparations due to protests from the British and US ambassadors, who said the invasion of Taiwan "would destabilize peace in the Far East."

Despite international pressure, in mid-May 1874, the 3,000-strong contingent of the Imperial Japanese Army under the command of Tsugumichi Saigo unauthorizedly set off to Taiwan. A little later, the Japanese authorities were forced to recognize the legitimacy of the campaign. On 22 May 1874, the Japanese gathered their troops in the Taiwanese port of Sheliao and began punitive action against the Paivan aborigines.

The natives reacted to the Japanese in a quite unfriendly manner, and they gave rise to the opening of hostilities by killing several Japanese soldiers, who carelessly went for a walk away from the camp. The next day, General Saigo sent a detachment of troops into the mountains, which, having destroyed the village and massacred most of the male population of the village, returned to the camp with very few casualties. After that, many tribes laid down their arms and voluntarily surrendered to the Japanese. Just a few mountain villages remained hostile.

The desire to weaken the enemy with a decisive blow prompted Saigo to direct his power against them, as the most powerful and stubborn of all his opponents. On June 13, the Japanese army, divided into three groups, entered the hostile territory from different directions. The Japanese moved without encountering strong resistance. But their situation was not easy. Natural conditions seriously complicated their path: torrential rain, typical for this time of year, flooding of rivers and their rapid flow, lack of roads and unfamiliar area entailed many hardships and difficulties.

And the health of the members of the expedition was adversely affected by constant dampness, intense heat and exhausting work. Many fell ill with fever.

The highlanders avoided open combat, which was unequal for them, while firing at the Japanese with impunity from behind the inaccessible rocks, and disturbing them with unexpected attacks. The combat losses of the Japanese were rather small – only 12 men. But 561 Japanese soldiers died of malaria. The Qing dynasty demanded the immediate withdrawal of Japanese troops from Taiwan.

Terashima, who succeeded Soejima as foreign minister, fearing diplomatic complications, sent Japanese Ambassador Okubo Toshimichi to Nagasaki to suspend the expedition.

In August 1874, Okubo arrived in China, where he began negotiations with Zongliyamen (Foreign Ministry).