Saitou Dousan was a SAMURAI and the father-in-law of Oda Nobunaga.
He originally was a priest, and then he worked as oil man.
Next he became a samurai and he finally took a position of the daimyou of the land of Mino (Current Gifu Prefecture).
It was rare case that a commoner was promoted to a daimyou, because Japanese people in those days regarded family's social standing is the most important thing,
People who made a great achievement as he did were only Houjou Souun and Toyotomi Hideyoshi.
He made his daughter marry Nobunaga for a political reason.
It's said that he said that "My sons will be subordinates of him sometime." when he saw Nobunaga first.
This episode means that at early stage, Dousan already spotted out Nobunaga's competence.
After he retired, he appointed his son Yoshitatsu as a successor.
However they came to dislike each other intensely, finally he was killed by Yoshitasu.
At that time, he left a will that he would leave the land of Mino to Nobunaga.
For that reason, Nobunaga attacked Mino many times, he conquered Mino at last.
It seems obvious that he was a great samurai even though he was assassinated by his son.
