The Yuki War (1440-1441): Yuki Ujitomo's Siege Defense with the Sons of Ashikaga Mochiuji

The Yuki War began when Yuki Ujitomo rose in arms at about the 3rd month of Eikyo 12 (1440) and ended after a siege of about a year, when Yuki Castle fell on the 16th day of the 4th month of Kakitsu 1 (1441, old calendar). Ujitomo had taken Haruomaru and Yasuomaru, sons of Ashikaga Mochiuji, into Yuki Castle.

Background

The war was preceded by the Eikyo Disturbance of Eikyo 10 (1438), in which Ashikaga Mochiuji was defeated and took his own life, and the Kamakura-fu came to an end. Yuki Ujitomo took two of Mochiuji's sons into Yuki Castle and rose in arms.

The shogunate side

The Kanto kanrei Uesugi Norizane sent his younger brother Kiyokata to attack Yuki Castle. On the shogunate side Uesugi Kiyokata was supreme commander, and commanders including Uesugi Mochitomo, Uesugi Mochifusa, Uesugi Noritomo, Imagawa Noritada and Ogasawara Masayasu are said to have joined. The Ogasawara of Shinano, the Takeda of Kai and the Nagao of Echigo were also mobilized. The families of the Kanto were divided over which side to take.

Those who joined the Yuki side

Yuki Ujitomo was the instigator. The forces in the Kanto that joined the Yuki side included Utsunomiya Tomotsuna, Oyama Hirotomo, Nasu Sukeshige and Satake Yoshihito.

The fall of the castle

Yuki Castle fell on the 16th day of the 4th month of Kakitsu 1 after a siege of about a year. Ujitomo is said by some accounts to have taken his own life and by others to have fallen in battle. His son Mochitomo is also said to have fallen in battle with him.

Result and aftermath

The shogunate side won. Haruomaru and Yasuomaru were captured and killed at Tarui in Mino. As a result the Uesugi extended their hold over the Kanto. The Yuki house was revived by Ujitomo's surviving son Shigetomo, but he was later assassinated by a retainer of the Tagaya family, and the next head, Ujihiro, died young, so the house declined again.