From Live Science:
What should you name a baby samurai? What food should a samurai bring to a battle? What is a samurai's most treasured possession? A newly translated 450-year-old book supposedly written by a renowned samurai provides answers to these and many other questions about the Japanese swordsmen.
Called "The Hundred Rules of War," the book is a series of songs that could be sung by samurai, who had never gone into battle. It was supposedly written in Japanese in 1571 by a famous samurai named Tsukahara Bokuden, who lived from 1489 to 1571, during a war-ridden time in Japan. Stories told about Bokuden claim that he fought in over 100 battles and slew hundreds of swordsmen.
The book was recently translated into English by Eric Shahan, who specializes in translating Japanese martial-arts texts. The book was first printed in Japanese in 1840, and has been republished in Japanese several times since then, Shahan told Live Science.
read more here @ Live Science