|Died||May 28, 1556 (aged 62)
Battle of Nagaragawa, Mino Province
He was also known as the Viper of Mino (美濃の蝮 Mino no Mamushi?) for his ruthless tactics. His honorific title from the Imperial Court was Yamashirō-no-kami and since he was a monk he was also called Saitō Yamashirō-nyudō-no-kami.
Around 1555, rumors began to circulate that Saitō Yoshitatsu was not in fact Dōsan's son; it was said that he was Yorinari's. It does not appear that Yoshitatsu had been aware of that possibility himself until he heard the rumors.
The circumstances surrounding this are unclear, however. One belief is that Dōsan, having had a number of sons after Yoshitatsu, had decided to name one of them heir (despite having officially retired by this point in favor of Yoshitatsu). Another theory holds that Yoshitatsu simply assumed that he would be disinherited, and decided to move first. A further idea is that Saitō Yoshitatsu just elected to usurp his father's power.
In desperation, Dosan is alleged to have named Nobunaga as lord of Mino in his will and sent this document to Nobunaga. Nobunaga, however, was unable to provide help.
Dōsan's head was taken by a certain Komaki Genta, a retainer of Yoshitatsu's son Tatsuoki. His remains were originally interred in Sōfuku-ji, but they were later moved to Jōzai-ji because the Nagara River kept overflowing and covering his burial mound. Both temples are located in Gifu.
Saitō Dōsan is known for having a large number of pseudonyms and for frequently changing his name. Some believe that this is because there were two Saitō Dōsan, father and son, and the son adopted his father's name after his death. Other names of Saitō Dōsan are Minemaru (峰丸), Hōrenbō (法蓮坊), Matsunami Shogorō (松浪庄五郎), Nishimura Kankurō Masatoshi (西村勘九郎正利), Shinkurō (新九郎), Nagai Norihide (長井規秀), and Saitō Sakondayu Toshimasa (斎藤左近大夫利政). The name Saitō was adopted from the former shugodai of Mino who had been overcome by the Nagai clan in the 1520s.
- Father: Matsuda Motomune (from Traditional story. from another version says that he was child of Shinzaemonzo , monk of Myoukaku-ji Temple)
- Wife: Omi no Kata ,daughter of Akechi Mitsutsugu
- Concubine: Miyoshi no Kata
- Nussbaum, Louis-Frédéric. (2005). "Saitō Dōsan" in Japan Encyclopedia, p. 809.
- Turnbull, Stephen (1987). Battles of the Samurai. Arms and Armour Press. p. 57. ISBN 0853688265.
- Sengoku Bushō Retsuden 12: Saitō Dōsan. Accessed September 20, 2007.
- Buke Kaden - Mino Saitō-shi. Harimaya. Accessed September 20, 2007.
- Turnbull, Stephen (1998). The Samurai Sourcebook. Cassell & Co. p. 211. ISBN 1854095234.
- Gifu City Walking Map. Gifu Lively City Public Corporation, 2007.