Bushido
Bushido (武士道 Bushidō), meaning "way of the warrior," is a Japanese code of conduct and a way of life, loosely analogous to the European concept of chivalry. Bushido developed between the 11th to 14th centuries as set forth by numerous translated documents dating from the 12th to 16th centuries (as mentioned below). According to the Japanese dictionary Shogakukan Kokugo Daijiten, "Bushido is defined as a unique philosophy (ronri) that spread through the warrior class from the Muromachi (chusei) period."
The core tenets of Bushido date from as early as the 12th century as demonstrated by the earliest translations of Japanese literature and warrior house codes. Bushido became formalized into Japanese feudal law under the Tokugawa Shogunate into Japanese Feudal Law.
Inazo Nitobe, in his book Bushido: The Soul of Japan, described it in this way. "...Bushido, 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."