Lifespan: Unknown to 6/28 of Kōji 3 (1557)
Other Names: Dentarō, Nobumasa
Title: Master of Imperial Guards of the Left Division (honorary)
Lord: Matsudaira Chikatada → Matsudaira Nagachika → Matsudaira Nobutada → Matsudaira Kiyoyasu
Father: Ishikawa Chikayasu
Ishikawa Tadasuke served as a bushō during the Sengoku period.
Tadasuke was born as the son of Ishikawa Chikayasu, a retainer of the Matsudaira of Mikawa Province.
Tadasuke was a member of the Ishikawa clan based in Ogawa in the Hekikai District of Mikawa. He served Matsudaira Chikatada, Matsudaira Nagachika, Matsudaira Nobutada, and Matsudaira Kiyoyasu. Later, he was counted among the Okazaki Group of Five, comprised of five elite retainers of Matsudaira Kiyoyasu including, in addition to Tadasuke, Amano Sadaari, Uemura Shinroku, Naitō Yoshikiyo, and Hayashi Tōsuke.
He attended his coming-of-age ceremony in the presence of Chikatada and Nagachika, and received one of the characters from the name of Chikatada, adopting the name of Tadasuke. Tadasuke plotted with his uncle, Ishikawa Yasunaga, from the base of the Ishikawa family in Ogawa and arranged for provincial samurai from the Honshō Temple in Nodera under the command of the Anjō-Matsudaira family. Tadasuke had bushi who were followers of the Hongan Temple of Mikawa serve the Anjō-Matsudaira family. This contributed to the subsequent development of the Matsudaira family.
His lord, Matsudaira Nobutada, was described by Ōkubo Tadataka in his account of Mikawa as lacking ability as a leader. Frivolous and stubborn, those refusing to abide by his rule ranged from members of the Matsudaira family to local citizens and peasants. Many declined to serve in the castle. There is a legend that Tadasuke lured Nobutada out of the castle on the pretext of meeting an attractive woman, and then apprehended and incarcerated him in the Shōmyō Temple in Ōhama.
According to one account, in 1523, Sakai Tadanao informed Nobutada of the outcome of a meeting of family member and accepted a request to retire, whereupon he transferred headship of the clan to his eldest son, Matsudaira Kiyoyasu, and retired at the age of thirty-four to the Ōhama township in the Hazu District of Mikawa.
Tadasuke died on 6/28 of Kōji 3 (1557).