In November 1869, by the order of the
Nagato domain's lord, he enlisted in
Fushimi Goshin Heisha () to be trained in the French style for the domanial Army. After completing the training, he was reassigned to the Kawatō Barrack in
Kyoto as an instructor, and then as Toyōra domain's Army trainer in charge of coastal defense troops. In 1871, Nogi was commissioned as a
major in the fledgling
Imperial Japanese Army. Around this time, he renamed himself
Maresuke taking a
kanji from the name of his father. In 1875, he became the 14th Infantry Regiment's attaché. The next year (1876), Nogi was named as the
Kumamoto regional troop's Staff Officer, and transferred to command the 1st Infantry Regiment, and for his service in the
Satsuma Rebellion, against the forces of
Saigō Takamori in
Kyūshū, he was promoted to
lieutenant colonel on April 22, 1877. In a fierce battle at that time, he lost the 14th Infantry Regiment's regimental banner, which was considered to be the property of the Emperor, to the enemy. Its loss was an extreme disgrace. Nogi considered this such a grave mistake that he listed it as one of the reasons for his later suicide. On August 27, 1876, Nogi married Shizuko, the fourth daughter of
Satsuma samurai Yuji Sadano, who was then 20 years old. As Nogi was 28 years old, it was a very late marriage for that time, considering that the average age to marry was in the early 20s. On August 28, 1877, their first son Katsunori was born, and Nogi bought his first house at Niizakamachi,
Akasaka, Tokyo. In 1879, his second son Yasunori was born. He was promoted to
colonel on April 29, 1880. He was posted to Nagoya during the early Meiji era. The warehouse in the Sannomaru enceinte of
Nagoya Castle was probably constructed in 1880 (Meiji 13) as an army ammunition depot. It was named later after him. Two years after his 1885 promotion to
major general, Nogi went to
Germany with
Kawakami Soroku to study European
military strategy and tactics. In 1894, during the
First Sino-Japanese War, Major-General Nogi commanded the First Infantry Brigade which penetrated the Chinese defenses and successfully occupied
Port Arthur in only one day of combat. As such, he was a senior commander during the
Port Arthur massacre. The following year, he was promoted to
lieutenant general (April 29, 1895) and assigned to the
Second Division, tasked with the
invasion of Taiwan. Nogi remained with the occupation forces in Taiwan until 1898. In 1899, he was recalled to Japan, and placed in command of the newly formed 11th Infantry Brigade, based in
Kagawa. == Political career ==