Lifespan: 15xx to 15xx
Rank: bushō; lord of Ōbasawa Castle
Lord: Uesugi Kenshin → Uesugi Kagetora → Uesugi Kagekatsu
Father: Ayukawa Kiyonaga
Children: Hidesada (adopted son of Ninomiya Nagatsune)
Ayukawa Morinaga served as a bushō and retainer of the Uesugi clan during the Sengoku and Azuchi-Momoyama periods. Morinaga was the lord of Ōbasawa Castle in Echigo Province. Morinaga was the son of Ayukawa Kiyonaga.
The Ayukawa clan were members of the Agakita Group – powerful landowners in northern Echigo who were fiercely independent. The Ayukawa controlled territory in the Iwafune District.
The Ayukawa descended from the same main family as the Honjō clan, but in the course of frequent clashes between the Honjō and the Uesugi, the Ayukawa always sided with the Uesugi and fought against the Honjō. Nevertheless, the Ayukawa hardly ever won in contests against the Honjō.
The death of Uesugi Kenshin on 3/13 of 1578 gave rise to a succession struggle between two of his adopted sons, Uesugi Kagekatsu and Uesugi Kagetora, an event known as the Otate Conflict. In this conflict, Honjō Shigenaga aligned with Kagekatsu and fought against Morinaga who sided with Kagetora. Despite Kagetora’s loss, Morinaga was permitted to return to the service of the Uesugi.
A quarrel in regard to the conferral of honors in the wake of the Otate Conflict triggered the Revolt of Shibata Shigeie. On this occasion, Morinaga decided not to align with either side so his fortunes declined.
Morinaga did not have any heir so he adopted Ninomiya Hidesada, the natural son of Ninomiya Nagatsune, a Shintō priest in Etchū Province. Hidesada served the Maeda clan of Kaga Province but, in 1639, his successor, Nobushige (the son of Honjō Nagafusa) served Uesugi Sadakatsu and reverted to a retainer of the Uesugi clan.