Ninja

A ninja (; ) or shinobi (; ) was a spy and infiltrator in pre-modern Japan. The functions of a ninja included siege and infiltration, ambush, reconnaissance, espionage, deception, and later bodyguarding. Antecedents may have existed as early as the 12th century. There is little evidence that they were assassins.

In the unrest of the Sengoku period, ''jizamurai'' families, that is, elite peasant-warriors, in Iga Province and the adjacent Kōka District formed ''ikki'' – "revolts" or "leagues" – as a means of self-defense. They became known for their military activities in the nearby regions and sold their services as mercenaries and spies. It is from these areas that much of the knowledge regarding the ninja is drawn. Following the Tokugawa shogunate in the 17th century, the ninja faded into obscurity. A number of ''shinobi'' manuals, often based on Chinese military philosophy, were written in the 17th and 18th centuries, most notably the ''Bansenshūkai'' (1676).

By the time of the Meiji Restoration (1868), ''shinobi'' had become a topic of popular imagination and mystery in Japan. Ninja figured prominently in legend and folklore, where they were associated with legendary abilities such as invisibility, walking on water, and control over natural elements. Much of their perception in popular culture is based on such legends and folklore, as opposed to the covert actors of the Sengoku period. Provided by Wikipedia