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.
In 1562, during the Siege of Kaminogo Castle, Kazumasa played a crucial role as Ieyasu successfully negotiated the release of his family from Imagawa Ujizane. Acting as their guardian, Kazumasa undertook this perilous duty with great responsibility. By 1567, Tokugawa forces were divided into two major divisions. Kazumasa was appointed commander of 13 Tokugawa daimyo-vassals, while Sakai Tadatsugu oversaw 18 daimyo-vassals.
Kazumasa fought in several critical battles, including the Battle of Mikatagahara in 1573 and the Battle of Nagashino in 1575. Following Toyotomi Hideyoshi's victory over Shibata Katsuie in 1583, Ieyasu conveyed his congratulations through Kazumasa. However, under Tokugawa orders, Kazumasa and Sakakibara Yasumasa later issued statements denouncing Hideyoshi. Kazumasa served at the Tokugawa headquarters in Komaki during the Komaki-Nagakute Campaign of 1584.
In 1585, Kazumasa became increasingly disillusioned with Ieyasu's defiance of Hideyoshi. Viewing this resistance as reckless, he defected to Hideyoshi’s side. This betrayal forced Ieyasu to overhaul his military organization and defense strategies, as Kazumasa had deep insights into Tokugawa operations.
After Hideyoshi's death and the establishment of the Tokugawa Shogunate, Kazumasa and his family faced punitive measures, losing their fief. Kazumasa eventually retired and spent his remaining years with his son, Ishikawa Yasunaga, until his death in 1609.
See also
-
Torii Mototada
Torii Mototada (1539 – September 8, 1600) was a Japanese samurai and daimyo who lived through the Sengoku and late Azuchi–Momoyama periods. A loyal retainer of Tokugawa Ieyasu, he is best remembered for his heroic last stand at the Siege of Fushimi, an event that played a crucial role in shaping Japanese history.
-
Toyotomi Hideyori
Toyotomi Hideyori (August 28, 1593 – June 4, 1615) was the son and designated successor of Toyotomi Hideyoshi, the general who first unified Japan. His mother, Yodo-dono, was Oda Nobunaga's niece.
-
Okubo Tadanori
Okubo Tadanori (January 13, 1842 – August 10, 1897) was the 9th daimyo of Odawara Domain in Sagami Province (modern-day Kanagawa Prefecture) during the late Edo period. Before the Meiji Restoration, he held the courtesy title of Kaga no Kami.
-
Okubo Tadayo
Okubo Tadayo (1532 – October 28, 1594) was a samurai general who served Tokugawa Ieyasu during the Azuchi–Momoyama period and later became the daimyo of Odawara Domain in the early Edo period.
-
Araki Murashige
Araki Murashige (1535 – June 20, 1586) was a samurai and retainer of Ikeda Katsumasa, the head of the powerful Settsu-Ikeda clan in Settsu Province. Initially serving under Katsumasa, he aligned himself with Oda Nobunaga after Nobunaga’s successful campaign to establish control over Kyoto.
-
Yuki Hideyasu
Yuki Hideyasu (March 1, 1574 – June 2, 1607) was a Japanese samurai who lived during the Azuchi–Momoyama and early Edo periods, serving as the daimyō of Fukui Domain in Echizen Province. Born Tokugawa Ogimaru, he was the second son of Tokugawa Ieyasu and Lady Oman (also known as Lady Kogō), a handmaiden to Ieyasu’s wife, Lady Tsukiyama. Due to Ieyasu’s fears of his wife’s reaction to Oman’s pregnancy, Ogimaru and his twin brother were born in secrecy at the home of Honda Shigetsugu, one of Ieyasu’s retainers. Oman’s other son eventually became a priest, while Ogimaru was raised apart from Ieyasu, whom he only met at the age of three, in a meeting arranged by his older half-brother, Matsudaira Nobuyasu.
-
Tsutsui Sadatsugu
Tsutsui Sadatsugu (June 6, 1562 – April 2, 1615) was a prominent figure in the Sengoku and early Edo periods, known as the cousin and adopted heir of Tsutsui Junkei, the feudal lord of Yamato Province. Following Junkei's death in 1584, Toyotomi Hideyoshi relocated Sadatsugu to Iga Province, where he oversaw the construction of Iga Ueno Castle, marking the height of his prominence.
-
Matsudaira Kiyoyasu
Matsudaira Kiyoyasu (September 28, 1511 – November 29, 1535) served as the 7th lord of the Matsudaira clan during Japan's tumultuous Sengoku period. Renowned as the paternal grandfather of Tokugawa Ieyasu, one of Japan's "great unifiers," Kiyoyasu expanded his clan’s influence, bringing all of northern Mikawa Province under his control after subduing the Saigo clan. His power was further symbolized by the construction of Okazaki Castle, a testament to the Matsudaira’s growing dominance.
