The son of Nanbu Nobunao and lord of Morioka castle, he supported Tokugawa Ieyasu during the Sekigahara Campaign, leading his men to aid Mogami Yoshiaki and Date Masamune against the forces of Uesugi Kagekatsu. After the campaign was concluded, Toshinao was confirmed in his 100,000 koku fief.
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005
- Edo daimyô hyakke 江戸大名百家. Bessatsu Taiyô 別冊太陽. Spring 1978. pp168, 187-188.
- Arai Hakuseki, Joyce Ackroyd (trans.), Told Round a Brushwood Fire, University of Tokyo Press (1979), 281n51.