Aki Province was in the Sanyōdō, or Sanyō Region, an area in the western portion of Honshū bordering the Seto Inland Sea.
In current terms, Aki corresponds to the western portion of Hiroshima Prefecture. The province was comprised of eight districts including Nuta, Kamo, Aki, Saeki, Yamagata, Takamiya, Takata, and Toyota.
1462-1475: Yamana Koretoyo
1475-xxxx: Yamana Masatoyo
- Aki-Takeda clan
- Mōri clan
- Kikkawa clan
- Kobayakawa clan
Shrines listed in the engishiki jinmyōchō (a directory of shrines published in the tenth century):
- Itsukushima Shrine (formerly 伊都岐島神社) in the Saeki District – regarded as an ichi-no-miya, or shrine of the first rank
- Hayatani Shrine in the Saeki District regarded as a ni-no-miya, or shrine of the second rank
- Take Shrine in the Aki District – regarded as a sōsha
1517: The Battle of Arita-Nakaide – also referred to as the Battle of Arita, triggered when Takeda Motoshige attacked Arita Castle defended by the Kikkawa clan in a failed bid to restore the power of the former shugo of Aki Province. This was the first battle for Mōri Motonari, who supported the Kikkawa.
1523: The Battle of Kagamiyama Castle – Amago Tsunehisa, Mōri Motonari, and kokujin from Aki Province against the Ōuchi army – the allied forces of the Amago and Mōri captured the castle while Kurata Fusanobu, lord of the castle and retainer of Ōuchi Yoshioki, killed himself following betrayal by his uncle, Kurata Naonobu, who was then killed by Tsunehisa.
1540-1541: The Battle of Yoshida-Kōriyama – Mōri Motonari and Sue Harukata (on behalf of the Ōuchi) against Amago Akihisa – the allied forces of the Mōri and Ōuchi won despite a force of 12,400 compared to 30,000 Amago forces, the Amago retreated, the Ōuchi expanded their area of control, and the Mōri established their dominance in Aki Province.
1554: The Battle of Oshikibata – Mōri Motonari against Sue Harukata (Miyagawa Fusanaga) – the Mōri won despite a force of 3,000 against 7,000 Sue forces; Miyagawa Fusanaga was killed.
1555: The Battle of Itsukushima – Mōri Motonari against Sue Harukata – the Mōri prevailed despite fielding 4,000 to 5,000 men compared to 20,000 – 30,000 Sue and Ōuchi forces.