Nagao no Masumi (長尾真墨)

NAGAO no Masumi (year of birth and death unknown) was a person from the Asuka Period in Japan.
In the old Japanese syllabary characters, his name was pronounced 'NAGAWO no Masumi.'
His Kabane (hereditary title) was Atai. In the Jinshin War which broke out in 672, NAGAO fought for Prince Oama (Emperor Tenmu) and participated in a series of wars to defend the enemy from Kawachi Province to Yamato (Yamato Province), but he was forced to retreat.

The Nagao clan was one of the Yamatonoaya clan, the families of immigrants from overseas to ancient Japan.

On August 1, 672, OTOMO no Fukei and his troops rose in arms in Yamato and headed for north, Nara (NARA City). In Hieda, on his way to Nara, probably on August 4, 672, Fukei got the information of the invasion of a large enemy force coming from Kawachi Province. Fukei organized three military units comprised of some hundred members for each and dispatched them for the defense. SAKAMOTO no Takara, NAGAO no Masumi, KURAKAKI no Maro, TAMI no Oshibi, and TANI no Ne Maro were involved in the troops as the commanders of the 300-member unit that headed for Tatsuta. After they set up camps at Hiraishino on the same day, the commanders were informed that there was the enemy in Takayasunoki Castle, so they climbed the mountain where the castle was located to attack the enemy. Omi forces (the army on the Emperor Kobun's side) fled from the castle after setting fire to storehouses.

In the next morning (5th) they saw a large enemy force led by IKI no Karakuni approaching from both Otsu-chi Road and Tajihi-michi Road which were located on the west side of the castle. They left the castle and advanced the troops across Egakawa River, and the battle broke out on the west side of the river. However, they were defeated and gathered at the camp which had been set up in Kashikosaka after the withdrawal. Among the troops of Karakuni, the winner, KUME no Shioko, Kawachi no kuni no kami (Governor of Kawachi Province), was gathering the troops to take the side of Prince Oama. Karakuni detected Shioko's betrayal, and Shioko committed suicide knowing that his plot was failed. Two days later, probably on 7, the commanders decided to pull out their troops as they saw Omi forces attacking from every direction.

NAGAO no Masumi was believed to have continued fighting for OTOMO no Fukei after this battle, but nothing was mentioned about him in "Nihonshoki" (Chronicles of Japan).