Career
Shigenaga served the Uesugi clan and was known for his betrayal against them. He held the court title Echizen no kami. Shigenaga fought at the Battle of Kawanakajima as rear left wing commander, acting as Uesugi Kenshin"s retainer.
He first murdered Nagao Fujikage, Uesugi"s vassal, and captured his castle.
This betrayal forced Kenshin to lay siege to Murakami castle held by Shigenaga Honjo. The conflict proved costly for Kenshin as Irobe Katsunaga, one of his generals, was slain in the battle and could not take the castle easily.
In spite of his rebellion against Kenshin, which lasted for one year, Takeda Shingen did not help him and Shigenaga was forced to surrendered to Kenshin under the coordination of the Ashina clan. After the siege he was pardoned by Kenshin
After the death of Kenshin in 1578 Shigenaga supported Uesugi Kagekatsu as successor during the Siege of Ōtate.
In 1588, Shigenaga once again entered conflict against the Mogami clan and Date clan wherein he defeated a Mogami army at the battle of Jugorihara(十五里ヶ原の戦い).
When Mogami Yoshiaki expanding his territory into the Shōnai region in Dewa province and threatened Yoshiuji Daihoji, who seek aids from Shigenaga. Together they successfully recovered Shōnai region as a territory of the Uesugi clan. In 1598, Uusegi Kagekatsu was transferred to Aizu Wakamatsu castle (Fukushima prefecture) by the Toyotomi government, and Shigenaga was transferred to the Aizu region.
Later on, during the conflict between the Toyotomi loyalists and Tokugawa Ieyasu, Shigenaga fought in a series of battles once again against Date Masamune and Mogami Yoshiaki at the Siege of Hasedō and Battle of Matsukawa.
Date"s forces attacked several times including rear attack from despite Date forces attempt to attack from mount Shinobu. In October 6, Shigenaga resisted an attack from Date Masamune"s warriors, such as Katakura Kagetsuna, Oniniwa Tsunamoto and Yashiro Kageyori.
Honjō Shigenaga was particularly known as the wielder of the famous blade Honjo Masamune, a katana representing the Shogunate during most of the Tokugawa Era. Shigenaga was attacked by Umanosuke who already possessed a number of trophy heads.
Shigenaga was attacked with the Honjo Masamune which split his helmet, but he survived and took the sword as a prize.
The blade was kept by Shigenaga until he was sent to Fushimi Castle, Bunroku around 1592-1595. Shigenaga ran out of funds and was forced to sell the sword to Toyotomi Hidetsugu, Toyotomi Hideyoshi"s nephew and retainer. lieutenant was bought for 13 Mai, 13 O-Ban, which was 13 large gold coins.
