1560: Battle of Okehazama and Regional Turmoil
The death of Imagawa Yoshimoto at the Battle of Okehazama shocked the nation. Taking this opportunity, Oda Nobunaga consolidated control over Owari, while Matsudaira Motoyasu (later Tokugawa Ieyasu) strengthened his independence in Mikawa. That same year, Uesugi Kenshin (Nagao Kagetora) prepared for a Kanto expedition in Echigo, and tensions rose between the Otomo and Shimazu clans in Kyushu, with upheavals and battles continuing across the country.
Events this year
Month 1
Saitō Yoshitatsu of Mino suddenly dies, and his heir Saitō Tatsuoki inherits the family leadership. The province becomes unstable.
Month 2
Mōri Motonari secures control of the Iwami Silver Mine, further strengthening his financial base.
Month 3
Nagao Kagetora (later Uesugi Kenshin) prepares for an advance into the Kantō region, continuing his rivalry with Hōjō Ujiyasu.
Month 4
Some kokujin resist the young Saitō Tatsuoki’s succession, with defections and secret communications with the Oda side.
Month 5
Imagawa Yoshimoto leads troops from Suruga, Tōtōmi, and Mikawa to invade Owari, capturing strongholds such as Odaka Castle and increasing pressure.
Kinoshita Tōkichirō (later Toyotomi Hideyoshi) successfully delivers provisions to Odaka Castle, earning Nobunaga’s trust.
Month 6
Takeda Shingen strengthens forces near Kawanakajima, restraining Uesugi-aligned kokujin mobilization.
6/12
Oda Nobunaga launches a surprise attack and slays Imagawa Yoshimoto, seizing dominance in Owari.
See this battle in detail →Sources 豊明市「桶狭間古戦場伝説地」／国立公文書館デジタル展示「徳川家康」／名古屋市博物館「五月の信長」
Month 7
Hōjō Ujiyasu brings several Kantō lords under his control, countering Uesugi influence.
Miyoshi Nagayoshi reorganizes Kinai control while negotiating with temple powers in Kii and Izumi.
Month 8
Matsudaira Motoyasu (later Tokugawa Ieyasu) returns to Mikawa’s Okazaki, advancing independence from Imagawa.
Chōsokabe Kunichika destroys the Aki clan, establishing control over most of Tosa.
Month 9
Signs of intensifying territorial struggle between Ōtomo Yoshishige (Sōrin) and Shimazu Yoshihisa.
Local lords loyal to Ōtomo and Shimazu repeatedly clash along the border.
Azai Nagamasa beat Rokkaku Yoshikata's army across the Uso River, and thereafter ruled northern Ōmi as an independent domain.
See this battle in detail →Sources 滋賀県教育委員会「近江戦国探訪ガイドブック２ 信長の城と戦国近江」／Wikipedia「野良田の戦い」
Month 10
Mōri Motonari attacks remnants of the Amago in San’in, expanding his sphere of influence.
Month 11
Uesugi Kenshin implements separation of farmers and soldiers and strengthens logistics in Echigo, preparing for the next year’s Kantō expedition.
Month 12
Shogun Ashikaga Yoshiteru seeks to improve relations with Kinai lords and temples to stabilize politics in Kyoto.