Born the eldest son of Kodama Hankurō Tadahiro, a samurai of Tokuyama domain in Suō Province (Yamaguchi). He lost his father as a small child, and his sister's husband Kodama Jirohiko took over the household. The family was far from wealthy, and Gentarō grew up supported by his mother and sisters.
Within the domain, the faction obeying the shogunate and the faction for revering the emperor and expelling foreigners clashed, and his brother-in-law Jirohiko, of the loyalist faction, was killed by opponents. The Kodama family's stipend was taken away and the household was forced into hardship. After this painful experience the boy Gentarō would later restore the family.
He took part as a soldier of Tokuyama domain in the Battle of Hakodate, the last battle of the Boshin War. He then entered the new government's forces (later the army), starting out from the lower ranks. He would open his own path by ability rather than by relying on family standing.
He joined the fighting to suppress the Saga Rebellion raised by Etō Shinpei and others, and was seriously wounded. Even so, his calm judgment on the battlefield was recognized, and he made his name as a young officer. Though small in build, he became known as a quick-thinking man who made decisions fast.
In the Satsuma Rebellion, as staff officer of the Kumamoto garrison under its commander Tani Tateki, he held out in Kumamoto Castle against fierce attacks by Saigō Takamori's army. Holding the castle contributed greatly to the government army's victory, and Kodama's skill in operations was highly praised.
He became director of studies (later head) of the Army War College and, with the German officer Meckel, who had been invited to Japan, organized the education of officers. Kodama eagerly learned modern operational thinking from Meckel and is said to have sat in on lectures among the students himself. This learning was put to use later in the Russo-Japanese War.
He became Governor-General of Taiwan, which had become Japanese territory after the Sino-Japanese War, and chose Gotō Shinpei as head of civil affairs, entrusting him with administration. The two pushed forward land surveys and the building of railways, ports and sanitation. At the same time, they also harshly suppressed resistance by the people of Taiwan.
While remaining Governor-General of Taiwan, he also served as Army Minister. Later he also served as Home Minister and Education Minister, showing his ability in politics as well though a soldier. Kodama, who worked extremely fast and handled many posts at once, is said to have been called a "genius" by those around him.
As war with Russia approached and the vice chief of the General Staff, Tamura Iyozō, suddenly died, Kodama resigned as Home Minister and took on the post of vice chief of the General Staff himself, a lower position in rank. It is known as a decision in which, at a time of national crisis, he chose duty over title.
When the Russo-Japanese War began, he supported commander-in-chief Ōyama Iwao as chief of staff of the Manchurian Army and took charge at the heart of operations. When the attack on Port Arthur ran into difficulty, he is said to have gone there himself and taken part in rethinking the assault. The trust between Ōyama and Kodama sustained the Japanese army.
After the Battle of Mukden, Kodama, knowing Japan's national strength was near its limit, quietly returned to Tokyo and strongly urged the government's leaders to end the war soon. Partly through his efforts, the war ended with the Treaty of Portsmouth, mediated by the United States.
He became chief of the General Staff, but that summer he died suddenly at his home in Tokyo, some say from the strain built up during the Russo-Japanese War. In Shūnan, Yamaguchi, there is a Kodama Shrine dedicated to him, and his decisive judgment and indifference to rank are still spoken of.
Saigō TakamoriEtō ShinpeiTani TatekiŌyama Iwao
Hoshi TōruOgino GinkoIsawa ShūjiTakamura KōunJosiah ConderKitasato ShibasaburōErnest FenollosaTakamine Jōkichi
People of the Meiji period ・ People by period
Based on facts found in textbooks and biographies. Uncertain points are marked as such.