Saitō Toshimasa

Saitō Dōsan 斎藤道三
Saitō Dōsan
Born	1494
Died	May 28, 1556 (aged 62) Battle of Nagaragawa, Mino Province

Saitō Dōsan (斎藤 道三, 1494 – May 28, 1556), also known as Saitō Toshimasa, was a Japanese samurai during the Sengoku period.

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.

Originally a monk, he later became a seller of oil. He became a daimyō through gekokujō of Toki Yorinari in Mino Province. The Saito fortress was located at Inabayama.

He married Ōmi no kata, a daughter of Akechi Mitsutsugu.

He defeated Oda Nobuhide at the Battle of Kanōguchi in 1547.

However, eventually Dosan was defeated by Oda Nobuhide and was forced to give his daughter in marriage to Nobunaga. Dōsan became the father-in-law of Oda Nobunaga.

In 1556, Saitō Dōsan fell in battle against forces led by his own adopted son, Saitō Yoshitatsu in the Battle of Nagara-gawa.

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.

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