The circle indicate the time we are discussing in this section
The above timeline shows two red circles. In political history, the Sengoku period (戦国時代) is a part of the Muromachi (室町) period, which is shown on the third line. However, in the sword history, we separate the Muromachi period and the Sengoku period (Warring States period), shown on the centerline. In sword history, we divide the time this way because, in those two periods, the sword style changed, and the environment of sword making also changed.
After the Onin-no-Ran (応仁の乱) had started (discussed in 20|Muromachi Period History(室町歴史) , the beautiful capital city, Kyoto (京都 ) was in a devastating condition. The shogun’s (将軍) power reached only to the very limited small area. The rest of the country was divided into 30 or so small independent states. The heads of those independent states were called Shugo Daimyo (守護大名). They were initially government officials, who had been appointed and sent there by the central government. Also, powerful local samurais often became the head of those states. They fought against each other to take over other’s land. During the Sengoku period, vassals would kill his master and stole his domain, or farmers would revolt against their lords. A state like this is called “Gekoku-jo (lower class samurai could overthrow the superior).”
This is the time of the Warring States called the Sengoku period. The head of a state was called Sengoku Daimyo (戦国大名: warlord). The Sengoku period lasts about 100 years. Little by little, powerful states defeated less powerful ones after long hard battles and gained more territory. Thirty or so small countries became 20, then ten and so on. Eventually, a few dominant Sengoku Daimyo (warlord) were left. Each daimyo of those states tried to fight his way up to Kyoto and unite the country. The first one who almost succeeded was Oda Nobunaga (織田信長). However, he was killed by his vassal, Akechi Mitsuhide (明智光秀), but shortly after, Akechi was killed by his colleague, Toyotomi Hideyoshi (豊臣秀吉)
After Toyotomi Hideyoshi defeated Akechi Mitsuhide and his troop and a few more significant warlords, he almost completed uniting Japan. Yet, Hideyoshi had one more rival to deal with to complete his job. That was Tokugawa Iyeyasu (徳川家康). Now, Toyotomi Hideyoshi and Tokugawa Ieyasu were the last contenders for the top position. Both knew that their opponents were smart and able. Any wrong move on either part would be a fatal mistake. So, they decided to keep an amicable co-existing relationship on the surface for a while. Though Toyotomi Hideyoshi tried to make Tokugawa Ieyasu his vassal, Tokugawa Ieyasu somehow maneuvered to avoid that. In the mind of Tokugawa Iyeyasu, since he was younger than Toyotomi Hideyoshi, he knew that he could just wait until Hideyoshi‘s natural death. At that time, he could destroy Hideyoshi’s heir. And that happened eventually.
After Hideyoshi’s death, Tokugawa Ieyasu fought Hideyoshi’s vassals and won at the Battle of Sekigahara (関ヶ原の戦い) in 1600. Then, in 1615, at the battle of the Osaka Natsu-no-Jin (大阪夏の陣), Tokugawa won against Hideyoshi’s son, Hideyori’s army. After this, the Toyotomi clan ceased to exist entirely, then the Edo (江戸) period started. The period is called the Edo period because Tokugawa Ieyasu lived in Edo, current Tokyo (東京).
*The Sengoku period is often depicted in TV dramas and movies. People who lived through the Sengoku period had a tough time, but it was the most exciting time for making TV shows and movies. The life of Oda Nobunaga, Toyotomi Hideyoshi and, Tokugawa Ieyasu is the most favorite story in Japan. Especially the story of Toyotomi Hideyoshi is one of the most popular ones. His background was a poor farmer, but he eventually became the top ruler of Japan. That is one fascinating success story.