was a general in the early

Imperial Japanese Army The Imperial Japanese Army (IJA; , ''Dai-Nippon Teikoku Rikugun'', "Army of the Greater Japanese Empire") was the principal ground force of the Empire of Japan from 1871 to 1945. It played a central role in Japan’s rapid modernization during th ...

. He was the older brother of General Ōsako Naomichi.Kowner, '' Historical Dictionary of the Russo-Japanese War'', p. 273.

Biography

Ōsako was born as the eldest son to Ōsako Shinzō, a

samurai The samurai () were members of the warrior class in Japan. They were originally provincial warriors who came from wealthy landowning families who could afford to train their men to be mounted archers. In the 8th century AD, the imperial court d ...

Satsuma Domain The , briefly known as the , was a Han system, domain (''han'') of the Tokugawa shogunate of Japan during the Edo period from 1600 to 1871. The Satsuma Domain was based at Kagoshima Castle in Satsuma Province, the core of the modern city of ...

(present day

Kagoshima Prefecture is a Prefectures of Japan, prefecture of Japan located on the island of Kyushu and the Ryukyu Islands. Kagoshima Prefecture has a population of 1,527,019 (1 February 2025) and has a geographic area of 9,187 Square kilometre, km2 (3,547 Square m ...

). He graduated from the domain’s Soshikan

academy An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of tertiary education. The name traces back to Plato's school of philosophy, founded approximately 386 BC at Akademia, a sanctuary of Athena, the go ...

, and fought as a Satsuma samurai during the Anglo-Satsuma War and the

Boshin War The , sometimes known as the Japanese Revolution or Japanese Civil War, was a civil war in Japan fought from 1868 to 1869 between forces of the ruling Tokugawa shogunate and a coalition seeking to seize political power in the name of the Impe ...

. He joined the fledgling Imperial Japanese Army in March 1871, and was assigned to the

Army Ministry The , also known as the Ministry of War, was the cabinet-level ministry in the Empire of Japan charged with the administrative affairs of the Imperial Japanese Army (IJA). It existed from 1872 to 1945. In the IJA and the Imperial Japanese Navy ...

from 1873 and promoted to captain in 1874. He was called to combat duty to fight against his fellow Satsuma clansmen in the

Satsuma Rebellion The Satsuma Rebellion, also known as the , was a revolt of disaffected samurai against the new imperial government of the Empire of Japan, nine years into the Meiji era. Its name comes from the Satsuma Domain, which had been influential in ...

, and was wounded during the siege of

Kumamoto Castle is a hilltop Japanese castle located in Chūō-ku, Kumamoto, in Kumamoto Prefecture. It was a large and well-fortified castle. The is a concrete reconstruction built in 1960, but a number of ancillary wooden buildings remain of the original ca ...

. During the war, he was promoted to major and served on the staff of the Kumamoto Garrison. Promoted to major in June 1883, Ōsako became commander of the IJA 6th Infantry Regiment and from May 1885 was assigned command of the 1st Guards Regiment. Promoted to colonel in 1887, he was chief-of-staff of the IJA 4th Infantry Division from October 1890 and appointed head of the 1st Bureau of the

Imperial Japanese Army General Staff Office The , also called the Army General Staff, was one of the two principal agencies charged with overseeing the Imperial Japanese Army (IJA). Role The was created in April 1872, along with the Navy Ministry, to replace the Ministry of Military Af ...

the following year. In September 1892, Ōsako was promoted to major general, and given command of the IJA 5th Infantry Brigade. Ōsako remained commander of the brigade throughout the

First Sino-Japanese War The First Sino-Japanese War (25 July 189417 April 1895), or the First China–Japan War, was a conflict between the Qing dynasty of China and the Empire of Japan primarily over influence in Joseon, Korea. In Chinese it is commonly known as th ...

, and was awarded after the war with elevation to the ''

kazoku The was the hereditary peerage of the Empire of Japan, which existed between 1869 and 1947. It was formed by merging the feudal lords (''Daimyo, daimyō'') and court nobles (''kuge'') into one system modelled after the British peerage. Distin ...

'' peerage with the title of

baron Baron is a rank of nobility or title of honour, often Hereditary title, hereditary, in various European countries, either current or historical. The female equivalent is baroness. Typically, the title denotes an aristocrat who ranks higher than ...

(''danshaku''), and the

Order of the Golden Kite Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * ...

, 3rd class. After the war, he returned to the General Staff Office, and was promoted to lieutenant general in April 1900, and commander of the IJA 7th Infantry Division. This division was unusual in that it was tasked both with the defense, and with the settlement of

Hokkaido is the list of islands of Japan by area, second-largest island of Japan and comprises the largest and northernmost prefectures of Japan, prefecture, making up its own list of regions of Japan, region. The Tsugaru Strait separates Hokkaidō fr ...

. With the start of the

Russo-Japanese War The Russo-Japanese War (8 February 1904 – 5 September 1905) was fought between the Russian Empire and the Empire of Japan over rival imperial ambitions in Manchuria and the Korean Empire. The major land battles of the war were fought on the ...

, Ōsako participated in the

Siege of Port Arthur The siege of Port Arthur (, ''Ryojun Kōisen''; , ''Oborona Port-Artura'', August 1, 1904 – January 2, 1905) was the longest and most violent land battle of the Russo-Japanese War. Port Arthur, the deep-water port and Russian naval base ...

, under the overall command of General

Nogi Maresuke Count , also known as Kiten, Count Nogi GCB (December 25, 1849September 13, 1912), was a Japanese general in the Imperial Japanese Army and a governor-general of Taiwan. He was one of the commanders during the 1894 capture of Port Arthur from ...

’s Third Army. His forces played a major role in the bloody Battle of 203 Meter Hill, where he also lost his third son. and afterwards fought at the

Battle of Mukden The , one of the largest land battles to be fought before World War I and the last and the most decisive major land battle of the Russo-Japanese War, was fought from 20 February to 10 March 1905 between Japan and Russia near Mukden ...

. He returned to Japan in March 1906, was awarded the Order of the Golden Kite, 2nd class in April and was promoted to general in May. In September 1907, he was also elevated from baron to viscount (''shishaku''). He entered the reserves in April 1909 and retired from service in April 1914. From November 1911, Ōsako replaced Nogi Maresuke as the principal of the

Gakushūin The , or , historically known as the Peers' School, is a Japanese educational institution in Tokyo, originally established as Gakushūjo to educate the children of Japan's nobility. The original school expanded from its original mandate of educ ...

Peer’s School, serving until August 1917. On his death in September 1927, he was awarded the Grand Cordon of the Order of the Rising Sun.

Decorations

* 1885 –

Order of the Rising Sun The is a Japanese honors system, Japanese order, established in 1875 by Emperor Meiji. The Order was the first national decoration awarded by the Japanese government, created on 10 April 1875 by decree of the Council of State. The badge feat ...

, 3rd class * 1895 - Order of the Sacred Treasure, 2nd class * 1895 – JPN Kyokujitsu-sho 2Class BAR

, 2nd class * 1895 – JPN Kinshi-kunsho 3Class BAR

, 3rd class * 1903 – Grand Cordon of the Order of the Sacred Treasure * 1906 – Grand Cordon of the Order of the Rising Sun * 1906 – JPN Kinshi-kunsho 2Class BAR

Order of the Golden Kite, 2nd class『官報』第2612号「号外」December 30, 1906 * 1927 – JPN Toka-sho BAR

Order of the Rising Sun with Paulownia Flowers

References

* * * *

Footnotes

{{DEFAULTSORT:Osako Naoharu 1844 births 1927 deaths People from Satsuma Domain Japanese generals Samurai Kazoku Grand Cordons of the Order of the Rising Sun Recipients of the Order of the Rising Sun with Paulownia Flowers Recipients of the Order of the Sacred Treasure, 1st class Recipients of the Order of the Golden Kite, 2nd class People of the Boshin War Japanese military personnel of the First Sino-Japanese War Japanese military personnel of the Russo-Japanese War