Because of their reliance on stealth and secrecy, there are not many records about the ninja. Scholars have to disentangle historical facts from legends. The ninja encouraged notions that they could fly, multiply their numbers, or even become invisible! Clans of ninja are thought to have emerged in the Lga and Koga mountain regions on Honshu, Japan's Largest island, by about the twelfth century AD. They were mostly poor peasants aimed to protect themselves from powerful samurai landowners. The ninja had to use their wits-they could not compete with the samurai's wealth and weapons. In time their reputation as effective assassins was such that they were employed by samurai lords. The ninja operated until the start of the Edo period (1603-1868), when more peaceful times meant a decline in the practice of martial arts and equipment. But ninja traditions are said to have continued underground, and recently they have been popularized by movies, books comics, and video games.