Even out of office as Japan's head of government, Itō continued to wield vast influence over the country's policies as a permanent imperial adviser, or genkun, and as the President of the Emperor's Privy Council.

In Asia, he oversaw the First Sino-Japanese War and negotiated the surrender of China's ruling Qing dynasty on terms aggressively favourable to Japan, including the annexation of Taiwan and the release of Korea from the Chinese Imperial tribute system.

While expanding his country's claims in Asia, Itō sought to avoid conflict with the Russian Empire through the policy of Man-Kan kōkan – the proposed surrender of Manchuria to Russia's sphere of influence in exchange for recognition of Japanese hegemony in Korea.

Consequently, Japan's incumbent prime minister, Katsura Tarō, elected to abandon the pursuit of Man-Kan kōkan, which resulted in an escalation of tensions culminating in the Russo-Japanese War.

He was a student of Yoshida Shōin at the Shōka Sonjuku and later joined the Sonnō jōi movement ("to revere the Emperor and expel the barbarians"), together with Katsura Kogorō.

[8] Itō was chosen as one of the Chōshū Five who studied at University College London in 1863, and the experience in Great Britain eventually convinced him Japan needed to adopt Western ways.

After the Meiji Restoration of 1868, Itō was appointed governor of Hyōgo Prefecture, junior councilor for Foreign Affairs, and sent to the United States in 1870 to study Western currency systems.

With the advice of Edmund Morel, a chief engineer of the railway department, Itō endeavored to found the Public Works together with Yamao Yozo.

In the same year, In 1885, Itō established a cabinet system of government based on European ideas, replacing the Daijō-kan as the nation's main policy-making organization.

[citation needed] On 30 April 1888, Itō resigned as prime minister, but headed the new Privy Council to maintain power behind-the-scenes.

Both the Liberal Party and the Shimpotō opposed his proposed new land taxes, and in retaliation, Itō dissolved the lower house of the Imperial Diet and called for general election.

[citation needed] Itō returned to office as prime minister for a fourth term from 19 October 1900, to 10 May 1901, this time facing political opposition from the House of Peers.

Weary of political back-stabbing, he resigned in 1901, but remained as head of the Privy Council as the premiership alternated between Saionji Kinmochi and Katsura Tarō.

On 25 November, he reached Saint Petersburg, having been asked by the new prime minister, Katsura Tarō, to sound out the Russians, entirely unofficially, on their intentions in the Far East.

Foreign minister Vladimir Lamsdorf "thought that time was on the side of his country because of the [Trans-Siberian] railway and there was no need to make concessions to the Japanese".

[citation needed] In Britain, Itō met with Lord Lansdowne, which helped lay the groundwork for the Anglo-Japanese Alliance announced early the following year.

[15] While Prime Minister, Itō invited Professor George Trumbull Ladd of Yale University to serve as a diplomatic adviser to promote mutual understanding between Japan and the United States.

On 17 November 1905, Itō and Japanese Field Marshal Hasegawa Yoshimichi entered the Jungmyeongjeon Hall, a Russian-designed building that was once part of Deoksu Palace, to persuade Gojong to approve the treaty, but the Emperor refused.

In 1907, he urged Emperor Gojong to abdicate in favor of his son Sunjong and secured the Japan–Korea Treaty of 1907, thereby giving Japan authority to dictate Korea's internal affairs.

While Itō was firmly against Korea falling into China or Russia's sphere of influence, he also opposed its annexation, advocating instead that the territory should be treated as a protectorate.

His body was returned to Japan on the Imperial Japanese Navy cruiser Akitsushima, and he was accorded a state funeral on 4 November 1909 at Hibiya Park.

In an entry for 28 October 1909, almost three years after being forced to abdicate his throne, the former emperor praised Itō, who had died two days earlier, for his efforts to develop Japanese civilization in Korea.

However, the integrity of Joseon silloks dated after the Japan–Korea Treaty of 1905 is considered dubious by Korean scholars due to the influence exerted over record-keeping by the Japanese.

Itō argued the Pan-Asian view that if East Asians did not co-operate closely with one another, Japan, Korea and China would all fall victim to Western imperialism.

[32] Korean intellectuals had predicted that the victor of the Russo-Japanese War would assume hegemony over their peninsula, and as an Asian power, Japan enjoyed greater public support in Korea than Russia.

However, policies such as land confiscation and the drafting of forced labor turned Korean popular opinion against the Japanese, a trend exacerbated by the arrest or execution of those who resisted.