Editing Ninja (section)

===Early history===
It was not until the 15th century that spies were specially trained for their purpose. It was around this time that the word ''shinobi'' appeared to define and clearly identify ninja as a secretive group of agents. Evidence for this can be seen in historical documents, which began to refer to stealthy soldiers as ''shinobi'' during the [[Sengoku period]]. Later manuals regarding espionage are often grounded in Chinese [[military strategy]], quoting works such as ''[[The Art of War]]'' by [[Sun Tzu]].<ref name="ratti 1991 324">{{Harvnb|Ratti|Westbrook|1991|p=324}}</ref>

By the Sengoku period, the ''shinobi'' had several roles, including spy (''kanchō''), [[Reconnaissance|scout]] (''teisatsu''), surprise attacker (''kishu''), and agitator (''konran''). The ninja families were organized into larger [[guild]]s, each with their own territories.<ref name="ratti 1991 327">{{Harvnb|Ratti|Westbrook|1991|p=327}}</ref> A system of rank existed. A ''jōnin'' ("upper person") was the highest rank, representing the group and hiring out mercenaries. This is followed by the ''chūnin'' ("middle person"), assistants to the ''jōnin''. At the bottom was the ''genin'' ("lower person"), field agents drawn from the lower class and assigned to carry out actual missions.<ref name="draeger smith 1981 121">{{Harvnb|Draeger|Smith|1981|p=121}}</ref>