The Mogami of Dewa province were descended from the Shiba family and were founded by Shiba Iekane's son Kaneyori; the Mogami increased their influence during the Sengoku Period and reached their peak after the Battle of Sekigahara; they were, however, to lose much of their wealth and influence due to the poor administration of Mogami Yoshitoshi in the early Edo Period.
References
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005