Lifespan: 15xx to 6/8 of Tenshō 10 (1582)
Clan: Mino-Andō clan
Lord: Saitō Tatsuoki → Oda Nobunaga
Father: Andō Morinari
Siblings: Sadaharu, Uemon-no-suke, Tokugetsu-in (formal wife of Takenaka Shigeharu), sister (formal wife of Endō Yoshitaka)
Andō Sadaharu served as a retainer of Saitō Tatsuoki and later for Oda Nobunaga. His roots were from the Andō clan of Mino Province. Sadaharu was the eldest son of Andō Morinari, who served as lord of Kitagata Castle in Mino and was known, together with Inaba Yoshimichi and Ujiie Naomoto, as one of the Nishi-Mino sanninshū, or West Mino Group of Three – powerful commanders of the Saitō clan in Mino. Sadaharu and Morinari are both frequently referred to with the Iga surname in period writings.
A writing dated in 1566 is jointly signed by Sadaharu along with Hineno Hironari, Takegoshi Naomitsu, and Ujiie Naomoto to inform the Takeda of Kai of recent developments in regard to Oda Nobunaga. For unknown reasons, it appears that Sadaharu signed as a representative of his father, Morinari. In 1567, Sadaharu followed Morinari by betraying the Saitō in favor of the Oda.
While serving the Oda, Sadaharu was assigned to Kōto Castle in Mino Province. In period accounts, Sadaharu’s name appears many times with his father, Morinari, beginning with the Battle of Okawachi in 1569 to the Battle of Arioka Castle in 1579, and there is some uncertainty as to whether certain of Sadaharu’s achievements are attributed to Morinari. In the Shinchō kōki, Sadaharu is first referenced in regard to the First Battle against the Ikkō sect of Nagashima at Arioka Castle in 1578.
Sadaharu issued a letter to Itō Sukemichi, a wealthy merchant in the textile trade together with his father, Sukehiro. The letter conveyed an order from Nobunaga for Sukemichi to take charge of the merchants in Mino. Sadaharu’s name also appears with attendees to a tea ceremony hosted by Tsuda Sōgyū in 1577.
In 1580, Sakuma Nobumori and his son, Nobumitsu, were found guilty of colluding with Takeda Katsuyori of Kai Province. A directive was then given to banish Morinari and the entire Andō clan from the Oda. The veracity of the charge of collusion with the Takeda is uncertain, but, under one theory, Sadaharu was implicated.
Following their expulsion from the Oda, the entire family was confined to the village of Taniguchi in the Mugi District of Mino under the supervision of Inaba Yoshimichi, while the Inaba clan absorbed their former territory.
In 1582, Nobunaga was killed in the dramatic coup d’etat at the Honnō Temple in Kyōto orchestrated by one of his senior retainers, Akechi Mitsuhide. Sadaharu joined his father, Morinari, by taking up arms and capturing Kitagata Castle from the Inaba in the former Andō territory. Several days later, this short-lived victory triggered a counterattack by the Inaba during which Morinari, Sadaharu, and his son, Chūshirō, all perished.