Honjō Shigenaga served as a bushō from the Sengoku to early Edo periods.  He was a senior retainer of the Uesugi clan.

In 1540, Shigenaga was born as the son of Honjō Fusanaga (Yamato-no-kami), a kokujin, or provincial landowner, in Echigo Province.  He was the grandson of Honjō Tokinaga.  His childhood name was Chiyoinomaru.

Just before Shigenaga was born, his father, Fusanaga, joined with fellow family members of the Irobe clan to oppose Nakajō Fujisuke who was an advocate for the adoption of Tokimunemaru, a son of Date Tanemune, by Uesugi Sadazane, the military governor of Echigo.  Fusanaga was attacked by the Nakajō clan who were supported by the Date clan.  Upon the recommendations of his younger brother (Ogawa Nagasuke) and another family member (Ayukawa Kiyoage), Fusanaga fled for the protection of the Mutō clan in the Shōnai area of Dewa Province with whom the Honjō had an alliance.  This, however, was a trap set by Nagasuke who took advantage of Fusanaga’s absence to seize control of his castle.  Overwhelmed by the rebellion led by his younger brother, Fusanaga fell ill and died.  After the loss of Fusanaga, the band of retainers of the Honjō clan attempted to install his orphan, Chiyoinomaru, as his successor, but were forced to accept Nagasuke as the guardian so that Nagasuke became the real holder of power in the clan.  In 1551, upon the occasion of the thirteenth anniversary of this father’s demise, Chiyoinomaru apprehended Nagasuke and forced him to kill himself and took over the clan.  Despite his youthful age, Chiyoinomaru was regarded as an intrepid character.

Shigenaga initially opposed Nagao Kagetora (later known as Uesugi Kenshin) who had supported Nagasuke, but, in 1558, he became a retainer, valorously participating in assorted contests including the Battle of Kawanakajima and attacks in the Kantō on behalf of Kenshin.  Nevertheless, as members of the Agakita Group comprised of landowners in the northern part of Echigo, the Honjō clan had a strong orientation toward autonomous rule, frequently clashing with military governors and deputy military governors from the Uesugi clan dispatched to the region.  In 1568, upon orders from Uesugi Kagetora (Kenshin), Shigenaga killed Nagao Fujikage and Nagao Kageharu (siblings), but was dissatisfied with the absence of a reward for his mission.  That same year, upon the urging of Takeda Shingen of Kai Province, he plotted to become independent of the Uesugi.  He then joined with Daihōji Yoshimasu, the head of the Daihōji clan (the Mutō clan) and lord of Oura Castle, to raise arms in an event known as the Revolt of Honjō Shigenaga.  Owing to Shigenaga’s intrepid tactics, Kenshin’s efforts to suppress him took longer than expected.  Kenshin first sent troops to the Shōnai area of Dewa to force the surrender of Yoshimasu, followed by fierce attacks against a then-isolated Shigenaga.  The next year, Ashina Moriuji mediated a surrender by Shigenaga who tendered his eldest son, Chiyomaru (later known as Honjō Akinaga), as a hostage.  Shigenaga was then allowed to return to the service of the Uesugi.

Thereafter, Shigenaga served under Kenshin until Kenshin’s death on 3/13 of Tenshō 6 (1578).  This gave rise to a succession struggle between two of his adopted sons, Uesugi Kagekatsu and Uesugi Kagetora, an event known as the Otate Conflict.  Shigenaga aligned with Kagekatsu and fought against the Ayukawa clan who sided with Kagetora.  Meanwhile, his eldest son, Akinaga, joined Daihōji Yoshiuji (Yoshimasu’s son) in support of Kagetora.  After Kagekatsu prevailed in the conflict, Shigenaga removed Akinaga from the line of succession.  Shigenaga then served Kagekatsu, and, as a retainer of the Uesugi, made significant contributions including the elimination of Shibata Shigeie.

In 1583, Daihōji Yoshiuji was killed by Mogami Yoshiaki, the lord of Yamagata Castle, who had plans to advance into the Shōnai area.  In a bid to prevent Yoshiaki’s invasion of the Shōnai, Shigenaga continued to support the Daihōji clan.  To strengthen his alliance with Shigenaga, Yoshiuji’s younger brother, Daihōji Yoshioki, welcomed Shigenaga’s second son, Senshōmaru, as an adopted son (later known as Daihōji Yoshikatsu or Mutō Yoshikatsu).  This, however, was fiercely opposed by kokujin aligned with the Mogami.  While Shigenaga was pinned down by attacks by the Shibata, resistance spread across the Shōnai, enabling Yoshiaki to advance his army into the area.  In the eleventh month of 1587, Oura Castle fell and Yoshioki killed himself while Yoshikatsu depended upon his father to flee.  In the eighth month of 1588, Shigenaga and his second son, Yoshikatsu, invaded the Shōnai while Yoshiaki was engaged in battle against Date Masamune.  At the Battle of Jūgorigahara, Shigenaga emerged victorious against allied kokujin opposed to the Mutō.  In pursuit of the Mogami forces, Shigenaga advanced to Higashine but encountered a surprise attack and withdrew.  In the fifth month of 1589, Shigenaga met Toyotomi Hideyoshi, upon which the Daihōji clan were publicly recognized as a security daimyō of Uesugi Kagekatsu.

In 1590, when, upon orders of Hideyoshi, Uesugi Kagekatsu conducted surveys of the Yuri and Senboku districts, a quarrel arose between Shigenaga and another senior retainer named Irobe Nagazane who was assigned to Ōmori Castle in the Hiraka District of Dewa Province.  Soon thereafter, the Senboku Uprising directed against the Toyotomi erupted in the Ouu region (Mutsu and Dewa provinces).  The uprising was quelled, but Shigenaga and Yoshikatsu (father and son) were suspected of instigating the Fujishima Uprising in the Shōnai.  The Toyotomi administration sent orders to the Uesugi family to mop-up the remnants of opposition forces whereupon the Uesugi led a large army into the Shōnai to fiercely suppress pockets of resistance.  This uprising led to the demotion and expulsion of Shigenaga and Yoshikatsu to Yamato Province.  Shigenaga was later pardoned owing to his participation in the Bunroku Campaign on the Korean Peninsula and awarded a fief of 10,000 koku, whereupon he returned to the service of the Uesugi.  In 1598, after Kagegatsu was transferred to Aizu, Shigenaga was appointed the chamberlain of Moriyama Castle in the Tamura District.

As the Battle of Sekigahara approached toward the end of the eighth month of 1600, upon orders of Kagekatsu, Shigenaga moved to Fukushima Castle in the Shinobu District.  Along with Suda Nagayoshi of Yanagawa Castle, he prepared for invasion by the Date army.  After the Battle of Sekigahara ended in victory for the Eastern Army, and Naoe Kanetsugu withdrew in defeat after attacking Mogami Yoshiaki, on 10/6, Katakura Kagetsuna, Moniwa Tsunamoto, and Yashiro Kageyori led the Date army on an attack against Fukushima Castle.  Shigenaga first sent Yoshikatsu to intercept the attacking forces, but these forces lost in a field battle between Miyashiro and Senoue, causing Yoshikatsu to withdraw and hole-up with Shigenaga in Fukushima Castle.  Isolated, the castle was then surrounded by Date forces who approached to the area below the castle.  A unit led by Isago Mitsune charged the castle gate to press the attack but learning that Iwai Nobuyoshi was coming from Miyashiro to attack along with marauding by the Suda, Shigenaga left the castle to take the offensive, resulting in a multi-pronged counterattack against the Date forces near the castle.  After incurring significant losses (including the killing of Kokubun Geki (a retainer of Katakura Kagetsuna) and Suda Yaheizaemon)), Masamune had to suspend the attacks and, after the rapid-firing of volleys from arquebuses into the castle, returned to their position on Mount Kunimi.  At this time, Suda Nagayoshi from Yanagawa Castle pursued the Date army who were assembling behind Mount Shinobu and attacked their logistics unit, enabling to capture the enemy battle flag.  According to accounts from the Date family, plans by the Date army that had gathered on Mount Kunimi to invite Yokota Daigaku at Yanagawa Castle to collude with the Date ended in failure so a second assault against Fukushima Castle was suspended and the forces retreated to Kitame Castle early on 10/7.  There is a theory that the forces withdrew by marching upstream along the Suriage RIver and from Moniwa via the Inego Pass to Kitame Castle.  In any event, Shigenaga valiantly held Fukushima Castle against the Date forces.

On 10/20, a military council was held to decide whether to continue to resist against, or to make peace with, Tokugawa Ieyasu.  At this session, Naoe Kanetsugu advocated to continue the resistance, while Shigenaga recommended a settlement.  Kagekatsu listened to Shigenaga’s advice and took steps to end the conflict.  On 11/3, he ordered Shigenaga to travel to Kyōto to negotiate a settlement.  Shigenaga collaborated with Chisaka Kagechika who was guarding Fushimi Castle to rapidly advance the peace process.  As a result, the efforts of Shigenaga and the others bore fruit so that the Uesugi family was permitted to survive, but subject to a reduction in their fief from 1,200,000 koku in Aizu to 300,000 koku in Yonezawa.  Meanwhile, Shigenaga’s fief was reduced to 3,300 koku but he was allowed to remain as the chamberlain of Fukushima Castle and, as a senior retainer of the Uesugi, worked toward their revival.

Shigenaga died on 12/20 at the age of seventy-four.  Uesugi Kagekatsu recognized his bravery, giving him the title of the God of War.  His memorial was established at the Chōraku Temple which, in 1600, was moved from Echigo to Mutsu Province.  He was succeeded by his second son, Daihōji Yoshikatsu, who returned to the Honjō family after an earlier adoption by the Daihōji and adopted the name of Honjō Mitsunaga.

Within the Uesugi family, Shigenaga was regarded as a fierce god.  He was treated very well by Uesugi Kagekatsu and as a member of the Uesugi family.  Kagekatsu permitted Shigenaga to inherit the vestiges of the family of Uesugi Kagenobu and to adopt the Uesugi family crest of a flying sparrow and bamboo.  The Honjō clan was the only one granted the special privilege to use the family crest other than the Yamaura family who were members of the Uesugi clan.