The circle indicate the time we are discussing in this section
According to the political history, Sengoku Period (戦国時代) is a part of the Muromachi (室町) period. But under sword history, we separate the Muromachi period and the Sengoku period (Warring States period). This is due to the sword style changed a little in those two times and the environment of sword making also changed in those two periods.
After Onin-no-Ran (応仁の乱) has started (discussed in 21|Muromachi Period), the beautiful capital city, Kyoto (京都 ) was in a devastating condition. The Shogun’s (将軍) power only reached the very limited small area. The rest of the counties were divided into 30 or so small independent countries. The head of those independent countries was called Shugo Daimyo (守護大名). They are government officials, originally appointed and sent by the central government. Also, powerful local Samurai became the head of the independent countries. Each of those countries fought against each other to take over each other’s land. During the Sengoku period, vassals killed his superior and stole his domain, farmers revolted against their lords. This is called “Gekoku-jo (lower class Samurai overthrow the superior)”. This is the time of the Sengoku period (Warring States period). The head of the domain was called Sengoku Daimyo (戦国大名 warlord). Sengoku period lasts about 100 years. Little by little, after long hard battles, stronger countries defeated less powerful countries and gained more territory. 30 countries became 20 then 10 and so on. Eventually, a few powerful big Sengoku Daimyo (warlord) were left. Each of those heads of the larger countries tried to fight his way up to Kyoto and unite the country. The first person who almost succeeded was Oda Nobunaga (織田信長). But he was killed by his own vassal, Akechi Mitsuhide (明智光秀), and Akechi was killed by his colleague, Toyotomi Hideyoshi (豊臣秀吉). After Toyotomi Hideyoshi defeated Akechi Mitsuhide and a few more major warlords, Toyotomi Hideyoshi almost completed uniting Japan. But one more person was left. That is Tokugawa Iyeyasu (徳川家康). Now, two big power clans were left. One is Toyotomi Hideyoshi and the other is Tokugawa Ieyasu. Both knew that their opponents are smart and powerful Daimyo, any wrong move on your part would be a fatal mistake. So they stayed co-existed amicably on the surface for a while, though Toyotomi Hideyoshi tried Tokugawa Ieyasu made his vassal, yet Tokugawa Ieyasu somehow maneuvered well 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. And that happened. After Hideyoshi’s death, Tokugawa Ieyasu fought with the vassals who used to be under Hideyoshi and won at the war of Sekigahara (関ヶ原) in 1600. Then 1615 Tokugawa won against Hideyoshi’s son, Hideyori’s army. After this, the Toyotomi clan ended completely, the Edo (江戸) period started. Edo period is called the Edo period because Tokugawa Ieyasu lived in Edo, which is Tokyo (東京) now.
*Sengoku period is often depicted on TVs and movies. People who lived through the Sengoku period had a very hard time but it is the most interesting time for TV shows and movies. Stories of Oda Nobunaga, Toyotomi Hideyoshi, and Tokugawa Ieyasu are the most favorite stories in Japan. Especially Toyotomi Hideyoshi’s story is one of the most popular ones. His background was a poor farmer and he became the top of Japan. This is one fascinating success story.