Ii Naomasa, recognized as one of the Four Guardians of the Tokugawa clan alongside generals Honda Tadakatsu, Sakakibara Yasumasa, and Sakai Tadatsugu, hailed from Hoda Village in Totomi Province (present-day western Shizuoka Prefecture). His family had long served Imagawa Yoshimoto until Yoshimoto's demise at the Battle of Okehazama.
Born to Ii Naochika, Naomasa faced familial upheaval when his father was unjustly accused of treason, leading to his exile and subsequent execution by Yoshimoto's son, Ujizane, in January of 1563. At the tender age of three, Naomasa, orphaned by this tragedy, was taken in by the Tokugawa family. Following the death of his stepmother, Naotora, in September of 1582, he assumed leadership of the Ii clan.
Commencing his service to the Tokugawa in the mid-1570s, Naomasa earned Tokugawa Ieyasu's high regard and was rewarded with a fief in Omi (Shiga Prefecture). Notably, at the Battle of Nagakute in 1584, he commanded 3,000 matchlock gunners and secured victory against Ikeda Tsuneoki's forces, earning commendation from the opposing leader, Toyotomi Hideyoshi. After this battle, Hideyoshi's mother was placed under Naomasa's care as a hostage to solidify the Toyotomi-Tokugawa alliance.
During the 1590 siege of Odawara, Naomasa played a pivotal role in breaching the castle walls, leading to the surrender of the Hojo clan. His efforts earned him Minowa Castle in Takasaki, Gunma, making him the largest landholder among Tokugawa retainers.
In 1600, at the Battle of Sekigahara, Naomasa and his son-in-law, Matsudaira Tadayoshi, initiated a daring attack on the Western allied Ukita troops, despite not being the first into battle as initially designated. Although surviving the intense seven-hour conflict, Naomasa sustained severe injuries in the final moments while pursuing the escaping Shimazu clan. Despite personal care from Ieyasu, the wounds from Sekigahara are believed to have contributed to Naomasa's premature death two years later.
In recognition of his valor, Naomasa was granted lands in modern-day Hikone. Disliking Ishida Mitsunari, the former owner of the area, to such an extent that he refused to live in his shadow, Naomasa had Ishida's castle on Sawayama demolished and significant topsoil removed from the mountain. Intent on establishing a new castle on Mt Hikone, he began construction but passed away before its completion.
See also
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Kyogoku Tadataka
Kyogoku Tadataka (1593–1637) was a Japanese nobleman and the head of the Kyogoku clan during the early 17th century, a pivotal time marked by the Tokugawa consolidation of power. His childhood name was Kumamaro, and he hailed from a lineage claiming descent from Emperor Uda (868–897). Tadataka was the son of Kyogoku Takatsugu and one of his concubines, with his paternal grandfather being Kyogoku Takayoshi.
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Matsudaira Naomasa
The late Muromachi period, also known as the Sengoku period, was an era of continuous conflict and upheaval, often likened to periods of chaos in Chinese history. This turbulent era was brought to an end by Tokugawa Ieyasu, who, with the support of loyal retainers, established the Edo Shogunate and became the ruler of Japan. Among Ieyasu’s descendants, Naomasa Matsudaira, his grandson, played a significant role during the Osaka Siege. He earned praise from his adversary, Nobushige Sanada (Yukimura Sanada), for his valor as a young warrior and maintained strong relations with successive Tokugawa shoguns.
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Ishikawa Kazumasa
Ishikawa Kazumasa (1534–1609) was a prominent Japanese retainer who began serving Tokugawa Ieyasu during his youth. Their relationship began in 1551 when both were hostages under the Imagawa clan. Kazumasa remained a loyal companion to Ieyasu, participating in key events such as the Siege of Terabe in 1558 and the Siege of Marune in 1560. After Ieyasu broke away from the Imagawa following the latter event, Kazumasa became a trusted retainer and administrator in his service.
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Shimazu Toyohisa
Shimazu Toyohisa (July 1570 – October 21, 1600), also known as Shimazu Tadatoyo, was a samurai of the Shimazu clan and the son of Shimazu Iehisa. He was the nephew of Shimazu Yoshihiro and held command over Sadowara Castle. Known for his valor, Toyohisa participated in numerous key battles of the late Sengoku period, earning recognition for his bravery and tactical acumen.
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Ikeda Terumasa
Ikeda Terumasa (January 31, 1565 – March 16, 1613) was a Japanese daimyo of the early Edo period, recognized by his court title, "Musashi no Kami," and known as the "Shogun of Western Japan." Terumasa, a distinguished military leader, participated in numerous significant battles during the late Azuchi-Momoyama period. His service at the Battle of Sekigahara earned him control over the Himeji domain. Originally named Araokojimaru, he was the son of Ikeda Tsuneoki and the brother of Ikeda Sen. He later became the heir to Ikeda Nobuteru and held Ikejiri Castle in Mino Province.
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Mori Tadamasa
Mori Tadamasa (1570 - July 31, 1634) was a notable military commander during Japan’s Warring States period and an early Edo-period daimyo. Initially, he governed Kawanakajima Domain in Shinano Province (modern-day Nagano Prefecture) and later became the first lord of Tsuyama Domain in Mimasaka Province (now northern Okayama Prefecture). He founded the Mori family line of the Ako Domain. Tadamasa’s family origins trace back to the Genji (Minamoto) clan, specifically the Kawachi-Genji branch from Kawachi Province (in present-day southeastern Osaka Prefecture), a lineage tied to Emperor Seiwa through his ancestor Yorisada Mori, a great-grandson of the famed Minamoto no Yoshiie.
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Sanada Masayuki
Sanada Masayuki (1547 – July 13, 1611) was a daimyo and prominent lord of Japan's Sengoku period. Head of the Sanada clan from Shinano Province, he served the powerful Takeda clan of Kai Province alongside his father and brothers during Takeda Shingen’s leadership. Following the Takeda clan's decline, Masayuki took charge of the Sanada, and despite limited resources, he established his clan as an independent power under the Toyotomi regime by navigating alliances with dominant clans such as the Tokugawa, Hojo, and Uesugi. Renowned as one of his era's greatest strategists, Masayuki achieved notable victories against the Tokugawa forces in the Battle of Kami River and the Siege of Ueda.
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Sanada Nobuyuki
Sanada Nobuyuki was a renowned samurai of the Sengoku period and the eldest son of daimyō Sanada Masayuki. He was the elder brother of the famous warrior Sanada Yukimura. Nobuyuki’s mother was Kansho-in, Masayuki's wife, and he was married to Komatsuhime (Inahime), the daughter of Honda Tadakatsu and the adopted daughter of Tokugawa Ieyasu. Nobuyuki also had two other wives: Seiin-in, his cousin, and Ukyo, the daughter of Tamagawa Hidemasa.
