Oda Nobunaga was the well-known lord of the Nagoya area (once called Owari Province) and an exceptional example of samurai of the Sengoku Period. He came within few years of, and laid down the path for his successors to achieve, the reunification of Japan under a new Bakufu (Shogunate).

Importantly, Toyotomi Hideyoshi (see below) and Tokugawa Ieyasu (http://www.samurai-source.com/samurai-warriors/togukawa-ieyasu.htm), who made Tokugawa Shogunate, were Nobunaga's (http://www.samurai-source.com/samurai-warriors/oda-nobunaga.htm) loyal followers. Hideyoshi was brought up from a nameless peasant to one of top generals under Nobunaga and Ieyasu had shared childhood with Nobunaga. Hideyoshi defeated Mitsuhide within a month and was regarded as the rightful successor of Nobunaga by avenging the treachery of Mitsuhide.

These two were gifted with Nobunaga's previous achievements to build the unified Japan. So there was a saying: "The reunification is a rice cake; Oda made it. Hashiba shaped it. At last, only Ieyasu tastes it." (Hashiba is the family name that Toyotomi Hideyoshi used while he was a follower of Nobunaga.)

Toyotomi Hideyoshi, who became a grand minister in 1586, himself the son of a poor peasant family, created a law that the samurai caste became codified as permanent and heritable, and that non-samurai were forbidden to carry weapons ending the social mobility of Japan up until that point and the dissolution of the Edo Shogunate by the Meiji revolutionaries.

It is important to note that distinction between samurai and non-samurai was so obscure that during the 16th century, most male adults in any social class (even small farmers) belonged to at least one military organization of their own and served in wars before and during Hideyoshi's rule. It can be said that an "all against all" situation continued for a century.

The authorized samurai families after the 17th century were the winners that chose to follow Nobunaga (http://www.samurai-source.com/samurai-warriors/oda-nobunaga.htm), Hideyoshi and Ieyasu (http://www.samurai-source.com/samurai-warriors/samurai-warriors.htm). Large battles occurred during the times of change between regimes, and a number of defeated samurai were destroyed, went Ronin (Wave-Men; or masterless Samurai) or were absorbed into the general populace.

Tokugawa Shogunate