Mōri Motonari

The Mōri and Kikkawa forces defeated Takeda Motoshige's army at Arita-Nakaide and killed Motoshige, an early Mōri victory that altered the balance of power in Aki.

Following the death of his nephew Komatsumaru, Mōri Motonari succeeded to the headship of the Mōri clan at the request of senior retainers. He became lord of Koriyama Castle and established the foundation for future expansion.

Mōri Motonari left the Amago camp for the Ōuchi and thereafter served as a military commander for the Ōuchi alliance in Aki and Bingo.

With aid from Ōuchi forces and the Wachi of Bingo and Shishido of Aki, Mōri Motonari destroyed the Amago-aligned Takahashi clan and established a leading position among warrior leagues in Aki, Bingo, and Iwami.

Amago Haruhisa attacked Yoshida-Koriyama Castle, but Mōri Motonari defended it with Ōuchi reinforcements.

Mōri Motonari transferred the headship to his eldest son Takamatsu. Even after stepping down, Motonari retained actual authority over military and diplomatic matters.

Mōri Motonari sent his second son Motoharu as an adopted heir to the Kikkawa clan and his third son Takataka to the Numata Kobayakawa clan, tasking them with commanding the Seto Inland Sea naval forces and defending the Sanin region.

Mōri Motonari, who had broken with the Suo clan, defeated Miyagawa Kai-no-kami of the Suo forces at Oshikibata. This victory led to the Battle of Miyoshima the following year, 1555.

Mōri Motonari crossed to Itsukushima, struck Sue Harukata's camp and broke it. The Ōuchi lost their grip on power and the Mōri rose in the Chūgoku region.

Mōri Motonari advanced into Suō and Nagato and took control of the former Ōuchi territories.

After the victory at Itsukushima, Mōri Motonari invaded Suō and Nagato, took Yamaguchi and drove Ōuchi Yoshinaga into Nagato. Yoshinaga took his own life at Chōfuku-ji and the Ōuchi house came to an end.

Mōri Motonari wrote and presented a fourteen-article letter of instruction to his three sons—eldest Takamatsu, second Motoharu, and third Takataka. The document emphasized the unity of the three brothers.

Mōri Motonari secures control of the Iwami Silver Mine, further strengthening his financial base.

Mōri Motonari attacks remnants of the Amago in San’in, expanding his sphere of influence.

Mōri Takamatsu died suddenly during an expedition to Izumo, and his grandson Terutoto succeeded to the headship. Motonari became Terutoto's guardian.

The Mōri army cornered the Amago clan's headquarters at Gassan-Toda Castle with a prolonged siege, and Amago Yoshihisa surrendered, causing the castle to open. The Mōri clan brought Izumo and Hōki under their control.