Saito Dosan

Saito Dosan: The Viper of Mino

Saito Dosan, also known as The Viper of Mino, was a prominent Japanese samurai and daimyo (feudal lord) during the Sengoku period. He was born in 1494 and gained fame for his ruthless tactics in battle, which earned him his infamous nickname. Dosan was originally an oil merchant from Kyoto, but he later became a retainer of Toki Yorinari, governor of Mino. He eventually ousted the Toki and assumed power of Mino, basing himself in Inabayama Castle.

Dosan was known for his ambition and cunning, which allowed him to rise to power despite his non-samurai background. He was also a skilled strategist and tactician, and he implemented several innovative military reforms during his rule. Dosan’s conquest of Mino and his establishment of a free-trade town helped to promote economic growth and prosperity in the region.

Today, Saito Dosan is remembered as one of the most influential figures of the Sengoku period, and his legacy continues to inspire admiration and fascination among historians and enthusiasts of Japanese history and culture.

Early Life

Saito Dosan, also known as the “Viper of Mino,” was born in 1494 in Yamashiro Province, which is located in southern Kyoto. He was not born into a samurai family, but rather, he was born into a family of monks. Despite this, Dosan would later become a samurai and a powerful daimyo in his own right.

As a young man, Dosan was sent to study at the Enryaku-ji temple on Mount Hiei, which was one of the most important Buddhist temples in Japan at the time. It was here that he would receive his education and training as a monk.

After completing his studies at the temple, Dosan returned to his hometown and became a monk at the local temple. However, he soon grew restless and began to seek out new opportunities. He eventually found work as a bodyguard for a local lord, which would be his first step on the path to becoming a samurai.

Dosan’s early life was defined by his desire to escape the limitations of his birth and to achieve greatness. He was a driven and ambitious young man who was not content to simply accept his lot in life. This drive and ambition would serve him well in the years to come as he rose to power and became one of the most feared and respected daimyos in Japan.

Rise to Power

Saito Dosan

Saito Dosan was born in 1494 and was a samurai during the Sengoku period. He was known for his ruthless tactics and was nicknamed “The Viper of Mino”. Dosan’s rise to power began when he became a merchant and conquered Mino, which he then converted into a free-trade town. This allowed the residents to prosper and obtain wealth.

Dosan’s success as a merchant led to him becoming a daimyo of the Mino province. He was able to establish himself as a powerful figure in the region and gained the respect of his peers. Dosan was also able to expand his territory by defeating the Toki clan when they attempted to invade Mino.

Dosan’s military success continued when he formed an alliance with the Oda clan. This prevented unnecessary bloodshed and allowed Dosan to focus on expanding his territory. He also arranged a marriage alliance with the Oda clan, which further solidified his power in the region.

Despite his success, Dosan’s ruthless tactics and ambition eventually led to his downfall. He was betrayed by his own son and was forced to commit seppuku in 1556. However, his legacy as a powerful and successful daimyo during the Sengoku period lives on.

The Viper of Mino

Saito Dosan was known as the Viper of Mino due to his ruthless tactics both on the battlefield and in administering his domain. He was a Japanese samurai during the Sengoku period, and his honorific title from the Imperial Court was Yamashiro-no-kami.

Dosan was an ambitious man who managed to seize the position of daimyo by overthrowing his former master. He was a merchant who had conquered Mino and converted it into a free-trade town, where the residents could prosper and obtain wealth.

Despite his reputation for being ruthless, Dosan was known for his strategic thinking and his ability to make alliances with other powerful figures. He had a history of clashing with the Oda clan of Owari Province, but their relations improved after he married off his daughter, Princess Noh, to Nobunaga, the Oda heir.

Overall, Dosan’s legacy is one of cunning and ambition, but also of strategic thinking and the ability to make alliances when necessary. His reputation as the Viper of Mino may have been well-deserved, but it was also a testament to his ability to outmaneuver his enemies and maintain his power in a tumultuous period of Japanese history.

Downfall and Death

Despite his success in making Mino a prosperous domain, Saito Dosan’s reign came to a tragic end. His own son, Saito Yoshitatsu, rebelled against him and defeated him in the Battle of Nagaragawa on May 28, 1556.

The reason for Yoshitatsu’s rebellion is not entirely clear. Some sources suggest that it was due to a power struggle between father and son, while others claim that it was because of Dosan’s harsh treatment of his son. Regardless of the reason, Dosan was defeated and killed by his own son.

After Dosan’s death, Yoshitatsu became the new ruler of Mino. However, his reign was short-lived as he was later overthrown by his own son, Saito Tatsuoki. Tatsuoki’s reign was marked by instability and conflict, and he was eventually defeated by Oda Nobunaga in 1567.

Despite his tragic end, Saito Dosan remains a significant figure in Japanese history. His innovative economic policies and military strategies helped to shape the political landscape of the Sengoku period, and his legacy continues to be studied and admired by historians and scholars today.


Despite his controversial reputation as a ruthless and cunning warlord, Saito Dosan left a lasting legacy in Japanese history. His military strategies and tactics were highly influential and were studied by other samurai leaders. He was also known for his architectural achievements, as he was responsible for the construction of several castles and fortresses throughout Japan.

One of the most notable castles built by Dosan was the Inabayama Castle, also known as the Gifu Castle. This castle was strategically located on top of a hill overlooking the city of Gifu, and it served as a key defensive stronghold during the Sengoku period. Today, the castle ruins are a popular tourist attraction in Japan.

Another aspect of Dosan’s legacy is his role in the history of the Mino Province. He was responsible for unifying the province under his rule, and he played a significant role in the political and economic development of the region. His influence can still be seen in the many festivals and cultural events that take place in the area, including the Gifu Nobunaga Festival.

While Dosan’s methods may have been controversial, there is no denying the impact that he had on Japanese history. His legacy as a military leader, strategist, and architect continues to be studied and celebrated to this day.