The Battle of Nejirozaka (根白坂の戦い)

The Battle of Nejirozaka was a battle fought between pro-Hideyoshi TOYOTOMI forces and pro-Yoshihisa SHIMAZU forces in Nejirozaka, Hyuga Province on May 24, 1587.

Course of events

Aiming to conquer Kyushu, Yoshihisa SHIMAZU launched an invasion of Bungo in 1586 and defeated the Toyotomi and Otomo allies in the Battle of Hetsugigawa in January 1587, on which occasion Yoshimune OTOMO fled to Buzen Province in fear of the power of the Shimazu clan, virtually leaving Bungo in control of the Shimazu clan.

Meanwhile, Hideyoshi TOYOTOMI, who had brought his old enemy Ieyasu TOKUGAWA into subjection to ensure future security, decreed a large-scale mobilization order in February, 1587 for the Kyushu Conquest, and sent a large army of daimyo (Japanese feudal lords) from Kinai (the five capital provinces surrounding the ancient capitals of Nara and Kyoto), Chugoku and Shikoku regions to Kyushu. In April, the forces of Hidenaga TOYOTOMI, who was Hideyoshi's younger brother, joined the Chugoku forces of Terumoto MORI, Hideie UKITA, and Keijun MIYABE who had already arrived at Buzen Kokura, making a 100,000-strong Toyotomi army. On this occasion, powerful local clans in Buzen and Bungo Provinces left the Shimazu clan and went over to the Toyotomi clan, and Masaie RYUZOJI and Naoshige NABESHIMA in Hizen Province followed their examples.

Seeing the wide military capabilities gap, Yoshihisa SHIMAZU planned to consolidate his forces. After the Battle of Hetsugigawa, Iehisa SHIMAZU, who was his younger brother, left Funai-jo Castle in Bungo which he had occupied and retreated to Matsuo-jo Castle (Hyuga Province) which was located further backward, and Yoshihiro SHIMAZU, who was his older brother, moved to Funai-jo Castle in Iehisa's place to reinforce the defenses. However, soon after the Funai-jo Castle was attacked by the Toyotomi's army, Yoshihiro SHIMAZU realized that the enemy's forces and supplies far exceeded his own, so he escaped Funai-jo Castle by sea in the midst of a midnight storm on April 22 and retreated to Matsuo-jo Castle where his younger brother Iehisa was on guard. This encouraged Chikatsugu SHIGA at Oka-jo Castle, which had been impregnable in the invasion of Bungo Province by the Shimazu army, and Myorinni at Tsurusaki-jo Castle. This combined with the pursuit of the Otomo army, claimed huge casualties in the Shimazu army and the army was forced to retreat to Hyuga. In the end of April, Hideyoshi TOYOTOMI invaded Hyuga, and on May 6, he took control of Matsuo-jo Castle, which was a key strategic point in northern Hyuga. Following the invasion, Hideyoshi besieged Taka-jo Castle, which was a key strategic point in southern Hyuga. However, Taka-jo Castle guarded by Arinobu YAMADA, who was a distinguished defense general of the Shimazu army, was impregnable and even the large army of Toyotomi couldn't take control of it easily.

Hideyoshi TOYOTOMI departed from Osaka on April 8, and arrived at an encampment in Kokura in Buzen Province on May 6. On May 8, Hideyoshi took control of Ganjaku-jo Castle, which was a subsidiary castle of Tanezane AKIZUKI of Chikuzen Province, which was a vassal province of the Shimazu clan. For fear of individual fortresses being attacked by Hideyoshi, Tanezane AKIZUKI abandoned and destroyed Masutomi-jo Castle, which was one of his branch castles, and all of his armed forces were besieged in Koshosan-jo Castle. But Hideyoshi, who was also a fortification expert, restored the destroyed Masutomi-jo Castle and used it as a military site, which shattered the morale of Tanezane and made him yield to Hideyoshi on May, 10. Hideyoshi went on to invade Chikugo Province on May 17, and marched into Kumamoto in Higo Province on May 23, and into Udo on May 24. During Hideyoshi's invasion, powerful local clans in various provinces yielded to Hideyoshi one after another in fear of Hideyoshi's power.

In the meantime, Yoshihisa SHIMAZU was panicked to hear Hideyoshi's army moving southward. Yoshihisa had gathered most of the troops from Satsuma and Osumi Provinces in Tonokori-jo Castle in Hyuga to prepare for Hidenaga's army. As a result, the guard in western Kyushu was sparse. The situation urged Yoshihisa to launch an attack on Hidenaga's army besieging Taka-jo Castle. At midnight on May 24, the Shimazu army raided Nejirozaka. Nejirozaka was a slope on the south of Taka-jo Castle, which was the only route for the Shimazu army to relieve Taka-jo Castle. Therefore, Hidenaga and Yoshikata KURODA heavily guarded Nejirozaka in preparation for an attack from behind by the Shimazu army.

Although opinions vary on the accurate numbers of the armies, it is said that the Toyotomi army numbered around 80,000 soldiers, whereas the Shimazu army numbered 35,000. The Shimazu army fought bravely, and legend has it that Yoshihiro SHIMAZU, who was the taisho (general) himself went to the front and fought in the battle.

But the Toyotomi army with 10,000 soldiers led by Keijun MIYABE, persistently protected the site utilizing karabori (dry moat) and a board fence. The Shimazu army couldn't break through the enemy and the battle entered a deadlock.

Then the main force of Hidenaga arrived to relieve the allies, but seeing the situation, Tomonobu BITO, who was a gungen (assistant deputy general), figured that relief was difficult and advised Hidenaga not to become engaged with the Shimazu army, to which Hidenaga followed.

But Takatora TODO's force with 500 soldiers under Hidenaga's command and Tatsuyasu TOGAWA's force under Hideie UKITA's command went off to relieve Keijun, which buffeted the Shimazu army. Then, forces of Kobayakawa and Kuroda joined to unleash a pincer attack, and the Shimazu army was hard hit and defeated.

The defeat in the major battle broke the morale of Yoshihisa SHIMAZU, who then took the tonsure, called himself Ryuhaku and surrendered to Hideyoshi TOYOTOMI on June 13. Subsequently, Ryuhaku talked Yoshihiro SHIMAZU and Tadamoto NINO out of their intention resist until the end, and the Shimazu clan completely yielded to Hideyoshi by the end of June.

Later, Yoshihisa SHIMAZU was given Satsuma, Yoshihiro SHIMAZU was given Osumi, Hisayasu SHIMIZU, who was a son of Yoshihiro SHIMAZU, was given a County in Hyuga, respectively. Thereafter, Yoshihisa transferred the head of the family to his younger brother Yoshihiro to launch a diarchy, and the Shimazu family retained the two Provinces and a County under the Toyotomi regime and Edo bakufu (Japanese feudal government headed by a shogun) until the Meiji period.