- Titles: Iyo no kami
- Distinction: Uesugi
Sadanaga was a retainer of Uesugi Kenshin famed for his skills as a warrior, and especially for his actions at the Second Battle of Kawanakajima (1555). He later supported Uesugi Kagetora in the Ôtate no ran and fled when the latter committed suicide in 1579. His younger brother Kagenaga remained in Uesugi service but was killed at Uzu castle in June 1582 fighting the forces of Shibata Katsuie.
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005