New Arrivals — Browse our catalog for the latest authentic Japanese sword arrivals. Browse →
The 7th to 8th days of the 1st month of Eiroku 7 (1564)
Kōnodai, Shimōsa Province (present-day Ichikawa City, Chiba Prefecture)
Forces
Later Hōjō Forces
Satomi Forces
About 15 min read
The Second Battle of Kōnodai was a Sengoku-period battle fought between the Later Hōjō and the Satomi on the 7th to 8th days of the 1st month of Eiroku 7 (1564) at Kōnodai in Shimōsa Province (present-day Kōnodai, Ichikawa City, Chiba Prefecture). The name "Second" distinguishes it from the battle fought at the same site in Tenbun 7 (1538) between Hōjō Ujitsuna and the forces of Ashikaga Yoshiaki, the Oyumi kubō, Satomi Yoshitaka, and others, which is known as the First Battle of Kōnodai. This battle became an important turning point in the Hōjō's conquest of Kantō and greatly reduced the power of the Satomi. The Kōnodai plateau overlooks the Edo River and was a strategic stronghold, and its strategic value was high as a traffic hub linking Musashi, Shimōsa, and Kazusa.
In the mid-Sengoku period, Kantō saw several forces repeatedly forming and breaking alliances: the Later Hōjō (the Hōjō of Sagami), the Satomi (a Sengoku daimyo of Awa), Uesugi Kenshin (Kantō kanrei and lord of Echigo), and the Koga kubō (the Ashikaga line). In Eiroku 3 (1560), Uesugi Kenshin (then Nagao Kagetora) led a large army into Kantō, and in Eiroku 4 (1561) he besieged Odawara Castle (the Siege of Odawara Castle). At this time Satomi Yoshihiro took part in Kenshin's Kantō expedition and played an important role as a force opposing the Later Hōjō. However, Kenshin withdrew to Echigo without defeating the Hōjō, and the daimyo of Kantō were drawn back into a complex contest of diplomacy and warfare.
After Kenshin withdrew to Echigo, the Hōjō strengthened their confrontation with the Satomi. At the end of Eiroku 6 (1563), Ōta Yasusuke, the castellan of Edo Castle on the Hōjō side, defected and fled to Ōta Sukemasa of Iwatsuki. Satomi Yoshihiro, who had been asked by Uesugi Kenshin to rescue the two men, entered Kōnodai early in the following year, Eiroku 7, with the Bōsō lords, and Hōjō Ujiyasu and Hōjō Ujimasa met them there. Absorbing former retainers of the Koga kubō and the Yamanouchi Uesugi, the Hōjō sought to establish hegemony over all of Kantō.
On the 7th day of the 1st month of Eiroku 7 (1564), both armies clashed across the Kōnodai plateau. It is said that the Satomi forces made use of their topographical advantage on the plateau and killed Tōyama Tsunakage and Tominaga Naokatsu of the Hōjō side, who had crossed the Edo River ahead of the others. However, because detailed primary sources are scarce, much of what is known about the specific course of the battle comes mainly from later war chronicles and regional gazetteers.
In the early hours of the following day, the 8th, the Hōjō forces again crossed the Edo River, made a surprise attack on the Satomi, and are said to have dealt them a crushing blow. Masaki Nobushige, a prominent Satomi commander, was killed in action. Nobushige was a brave commander who had succeeded to the name of his father, Masaki Tokishige ("Yari Daizen"), and his death was a great blow to the Satomi. Yoshihiro narrowly escaped the battlefield and fled to Awa. As a result of this defeat, the Satomi lost most of Kazusa Province and were for some time forced into a defensive retreat to Awa Province (the southern part of the Bōsō Peninsula).
Through this victory, Hōjō Ujiyasu extended his power into Shimōsa and Kazusa. In the same year, while maintaining the Kō-Sō-Sun Tripartite Alliance with the Takeda and the Imagawa, Ujiyasu built a stable system of control over southern Kantō.
The Second Battle of Kōnodai, as a battle showing the military peak of the Later Hōjō in the Sengoku east, is also closely tied to the history of swords. The Hōjō held the sword-making region of the Sōshū-den (Sagami Province and the area around Kamakura) as their base and under their control, and Sagami Province was the land that produced master smiths of the Sōshū-den such as Masamune, Sadamune, Hiromitsu, and Akihiro.
Hōjō Ujiyasu himself is highly regarded as a warlord who excelled not only in martial strategy but also in political ability. Detailed records of the swords he favored have not survived.
Masaki Nobushige, who died in this battle, is also remembered in later ages as a brave commander who supported the Awa Satomi. The Kōnodai area lies within Ichikawa City, which still retains its historical context, and it carries the memory of the Sengoku blades meeting there up to the present.
After the Second Battle of Kōnodai, the Satomi were for a long time on the defensive against the Hōjō. However, at the Battle of Mifuneyama in Eiroku 10 (1567), Satomi Yoshihiro defeated the Hōjō forces and succeeded in a certain counterattack. The Sengoku history of Kantō continued to unfold afterward, with forces such as the Hōjō, Uesugi, Takeda, Satomi, and Satake intertwining in complex ways. In Tenshō 18 (1590), the Odawara campaign of Toyotomi Hideyoshi (the fall of the Hōjō) brought an end to the Later Hōjō's rule of Kantō, and a great turning point in Japanese history followed, leading to Tokugawa Ieyasu's transfer to Kantō. As a memory of the eastern warriors that symbolizes the turmoil of that age, the Kōnodai battle is quietly inscribed at the crossroads of history and swords.
The First Battle of Kōnodai (Tenbun 7, 1538) was the battle in which Hōjō Ujitsuna defeated the forces of Ashikaga Yoshiaki, the Oyumi kubō, Satomi Yoshitaka, and others, and it became a turning point at which the Later Hōjō rose as the dominant power in southern Kantō. The Second Battle, fought at the same Kōnodai 26 years after this First Battle, shows the consistency of the Hōjō eastern strategy. Kōnodai was not merely an accidental battlefield but a strategic base that was repeatedly and deliberately chosen as a key point for Kantō's transport and military affairs.
The military organization of the Hōjō was remarkably systematic even among the daimyo of Kantō. Their skill in managing their domains, their favorable policies toward farmers, and the rationality of their castle construction are known as the strengths of the Later Hōjō. From the perspective of swords as well, the Hōjō held the sword-making region of Sagami Province and stood in a position to protect the heirs of the Sōshū-den. Throughout the Sengoku period, the techniques of the Sōshū-den were in decline, but there were also smiths who kept the tradition alive under Hōjō rule.
The Satomi were a Sengoku daimyo based in Awa Province (present-day southern Chiba Prefecture), and they formed a distinctive cultural sphere on the Bōsō Peninsula. Awa was a maritime province, skilled in operating naval forces, and it took in cultural goods from various regions through coastal trade. Records of the swords carried by Satomi warriors are fragmentary.
Swords of warriors who fell on the battlefield were often carried off by the victors as spoils of war. What became of the sword worn by Masaki Nobushige, who died in the Second Battle of Kōnodai, is unknown. Changes in the owners of swords brought about by battles like this produced the complex history peculiar to the transmission of Japanese swords. When one traces the provenance of swords held in modern museums, routes such as Sengoku battles, spoils of war, and gifts often emerge. The Battle of Kōnodai also quietly marks one page in this history of sword transmission.
In Tenshō 18 (1590), 26 years after the Second Battle of Kōnodai, Odawara Castle, surrounded by the great army of Toyotomi Hideyoshi, surrendered, and the Later Hōjō fell. Through the Odawara campaign, a considerable part of the treasures and sword collection that the Hōjō had accumulated was dispersed. Sōshū-den swords and famous inherited blades that had been gathered over the hundred years during which the Hōjō ruled Sagami were scattered across various regions at that point. Meanwhile, the Satomi submitted to Hideyoshi in the Odawara campaign and were permitted to survive in Awa Province. The fates of the swords of the Hōjō and the Satomi, who had confronted each other in the Second Battle of Kōnodai, were once again swept up in the waves of history 26 years later in Tenshō 18, and they came to be transmitted to later ages by different routes.