Battle of Arita-Nakai

By 1517, Takeda Motoshige, lord of Kanyama Castle, was probably the most influential daimyo in Aki Province. Ten years earlier, he had served as a vassal of the Ōuchi clan and participated in Ōuchi Yoshiyuki's campaign in Kyoto. This campaign was part of an effort to support the deposed shogun Ashikaga Yoshitane.

However, relations between the Ōuchi and Takeda clans were difficult and not mutually beneficial. At the end of the 15th century, taking advantage of internal strife within the Takeda clan, the Ōuchi invaded their lands and forced them to swear allegiance. When Motoshige was able to return to Aki, he enlisted the support of the Amago clan and freed himself from the Ōuchi's imposed “guardianship.”

The death of Mori Okimoto

In 1516, Mori Okimoto, the daimyo of the neighboring Mori clan, died unexpectedly. His youngest son, Komatsumaru, became his heir. The situation of weakened power was too tempting for rivals, and Takeda Motoshige decided to take advantage of it. Knowing that the main forces of the Ouchi clan were still in Kyoto, he gathered an army of about 5,000 warriors and invaded the lands of the Kikkawa clan, an ally of the Mori. Takeda laid siege to Arita Castle, which was commanded by Oda Nobutada.

The Mori's challenge

A few weeks later, Motoshige launched a raid deep into the Mori clan's territory. He set fire to the village of Tajihi, hoping to force Mori into open battle.

Mori's army was led by Motonari, the younger brother of the late Okimoto and guardian of the young Komatsumaru. He was only twenty years old, and this was his first military campaign.

Motonaori's Preparations

Motonaori could not count on the help of Ouchi's troops, so he mobilized his own vassals. Awa, Fukuhara, Inoue, Kutiba, and Watanabe gathered under his banners. In total, he managed to gather about seven hundred warriors, who were joined by another three hundred fighters from the Kikaw clan.

These forces marched towards Arita Castle. On the way, they encountered the vanguard of Takeda's army, numbering five hundred men, commanded by Kumagai Motonao.

The death of Kumagai Motonao

The allied forces stopped and opened fire on the enemy with their bows. Motonao himself was in the front ranks, encouraging his warriors and inspiring them to fight. But this cost him his life — he was struck by an enemy arrow.

The battle at the Matauti River

At that time, Motoshige was with the main forces at Arita Castle. Upon learning of the defeat of the vanguard, he gathered his troops and led them to avenge their fallen comrade. Takeda's army attacked the forces of Mori and Kikkawa, who had taken up positions on the opposite bank of the Matauti River.

Takeda had a numerical advantage. The allied forces faltered and were ready to retreat. They were held back only by Motonari's constant exhortations and personal presence.

The death of Motoshige and Mori's victory

At that moment, Motoshige himself rushed into battle. He forced his way across the river on horseback, but was almost immediately struck by a well-aimed arrow and fell on the battlefield.

The death of their leader was a turning point. Takeda's troops fled, and Motonari was victorious.

Consequences

This victory paved the way for the rise of the Mori clan. From that moment on, their influence grew not only in the province of Aki, but throughout the Chugoku region.