was a Japanese samurai of the Sengoku

Sengoku period

The or Warring States period in Japanese history was a time of social upheaval, political intrigue, and nearly constant military conflict that lasted roughly from the middle of the 15th century to the beginning of the 17th century. The name "Sengoku" was adopted by Japanese historians in reference...

 through late Azuchi-Momoyama period

Azuchi-Momoyama period

The came at the end of the Warring States Period in Japan, when the political unification that preceded the establishment of the Tokugawa shogunate took place. It spans the years from approximately 1573 to 1603, during which time Oda Nobunaga and his successor, Toyotomi Hideyoshi, imposed order...

s. Served as an officer under the Oda clan

Oda clan

The was a family of Japanese daimyo who were to become an important political force in the unification of Japan in the mid-16th century. Though they had the climax of their fame under Oda Nobunaga and fell from the spotlight soon after, several branches of the family would continue on as daimyo...

. At first, he was attached to Shibata Katsuie

Shibata Katsuie

or was a Japanese military commander during the Sengoku Period who served Oda Nobunaga.-Biography:Katsuie was born in the Shibata family, a branch of the Shiba clan . Note the differences between , , and the .Katsuie was the retainer of Oda Nobukatsu...

. After Oda Nobunaga

Oda Nobunaga

was the initiator of the unification of Japan under the shogunate in the late 16th century, which ruled Japan until the Meiji Restoration in 1868. He was also a major daimyo during the Sengoku period of Japanese history. His opus was continued, completed and finalized by his successors Toyotomi...

's death during the year of 1582, Nagayori fought against Toyotomi Hideyoshi

Toyotomi Hideyoshi

was a daimyo warrior, general and politician of the Sengoku period. He unified the political factions of Japan. He succeeded his former liege lord, Oda Nobunaga, and brought an end to the Sengoku period. The period of his rule is often called the Momoyama period, named after Hideyoshi's castle...

.

After Katsuie met his death, Nagayori went on to serve under Maeda Toshiie

Maeda Toshiie

was one of the leading generals of Oda Nobunaga following the Sengoku period of the 16th century extending to the Azuchi-Momoyama period. His father was Maeda Toshimasa. He was the fourth of seven brothers. His childhood name was "Inuchiyo" . His preferred weapon was a yari and he was known as...

, and Hideyoshi. Nagayori sided with Ishida Mitsunari

Ishida Mitsunari

Ishida Mitsunari was a samurai who led the Western army in the Battle of Sekigahara following the Azuchi-Momoyama period of the 17th century. Also known by his court title, Jibunoshō...

 during the Battle of Sekigahara

Battle of Sekigahara

The , popularly known as the , was a decisive battle on October 21, 1600 which cleared the path to the Shogunate for Tokugawa Ieyasu...

, but ended up being defeated. Nagayori took Mitsunari's life to assume the responsibility for the event.