Bushidō literally "the way of the warrior", was a Japanese word for the way of the samurai life, loosely analogous to the concept of chivalry.
"Bushido" is a modern term rather than a historical one. The "way" itself originates from the samurai moral values, most commonly stressing some combination of frugality, loyalty, martial arts mastery, and honor unto death. Born from Neo-Confucianism during times of peace in Tokugawa Japan and following Confucian texts, Bushido was also influenced by Shinto and Zen Buddhism, allowing the violent existence of the samurai to be tempered by wisdom and serenity. Bushidō developed between the 16th and 20th centuries, debated by pundits who believed they were building on a legacy dating back to the 10th century, although some scholars have noted that the term bushidō itself is "rarely attested in premodern literature".
Under the Tokugawa Shogunate, some aspects of warrior values became formalized into Japanese feudal law.
In Bushido (1899), Nitobe wrote: ...Bushidō, then, is the code of moral principles which the samurai were required or instructed to observe.... More frequently it is a code unuttered and unwritten.... It was an organic growth of decades and centuries of military career. In order to become a samurai this code has to be mastered. Nitobe was not the first to document Japanese chivalry in this way. In Feudal and Modern Japan (1896), historian Arthur May Knapp wrote: "The samurai of thirty years ago had behind him a thousand years of training in the law of honor, obedience, duty, and self-sacrifice.... It was not needed to create or establish them. As a child he had but to be instructed, as indeed he was from his earliest years, in the etiquette of self-immolation."