1570: Full-scale Formation of the First Anti-Nobunaga Coalition
The defection of Azai Nagamasa became evident with the retreat at Kanegasaki. Although the Oda–Tokugawa alliance won the subsequent Battle of Anegawa, the Ishiyama War began, expanding the front. The Siege of Shiga underscored the tense situation in the Kinai region, heightening pressures that would culminate in the burning of Mount Hiei the following year.
Events this year
Spring
Mōri Terumoto fortifies Gassan-Toda Castle to block Amago remnants and Oda advances.
Month 4
During the Echizen campaign, Azai Nagamasa suddenly defects. Oda Nobunaga faces encirclement by Asakura Yoshikage but retreats successfully thanks to rearguard actions.
Summer
The Amago restoration army, led by the returned-to-lay-life Amago Katsuhisa with Yamanaka Yukimori, briefly seized much of Izumo, but was heavily defeated at Mt. Fube by the returning main Mori force under Mori Terumoto, Kikkawa Motoharu and Kobayakawa Takakage, and its strength was greatly reduced.
Sources 戦国ヒストリー「布部山の戦い（1570年）」
Month 7
Capitalizing on victory at Anegawa, Ieyasu strengthens control in Mikawa and Tōtōmi, subduing rivals and building new castles.
Autumn
Having subdued the Motoyama and Aki clans, Chosokabe Motochika controlled central and eastern Tosa. The remaining rivalry with the Ichijo clan of western Tosa (Hata district) would be the final stage of his unification of the province.
Sources 高知県公式「長宗我部元親と土佐の戦国時代」
Within Satsuma, clans such as the Togo and Iriki-in submitted and unification progressed, while in neighboring Osumi, powerful local lords such as the Kimotsuki still resisted.
Sources 鹿児島県公式「島津家の内紛・三州の統一」
7/30
In Ōmi, Oda–Tokugawa allied forces defeat the Azai–Asakura alliance, expanding their influence by securing northern Ōmi castles.
See this battle in detail →Sources Wikipedia「姉川の戦い」
Month 8
Kennyo of the Ishiyama Hongan-ji in Settsu rises against Nobunaga, starting a prolonged war involving Ikkō sect followers.
See this battle in detail →Sources 大阪市「石山（大坂）本願寺推定地」／大阪市「大阪市の歴史－タイムトリップ20,000年」
Month 9
In Settsu, Oda forces attack strongholds of the Miyoshi Triumvirs and Hongan-ji, but retreat when Azai–Asakura advance south.
See this battle in detail →Sources 大阪市「7．野田城（のだじょう）跡」（福島区玉川四丁目11）／大阪市福島区「名所・旧跡」
Month 10
In Ōmi, Oda clashes with Azai, Asakura, and Hongan-ji forces near Sakamoto–Ōtsu. Mediated by Enryaku-ji, the stalemate continues into the following year.
Winter
Nanbu clan eases conflict with Andō in Tsugaru, maintaining control over northern trade routes.