Warmatrix

Shinobi a.k.a. ninja were the spies and infiltrators of feudal Japan. Like the Middle Eastern Hashashin they were not regular army troops. Unlike the Hashashin, they were not just assassins. They also engaged in spying, sabotage, infiltration and guerrilla warfare.
The first reported use of shinobi is from the 6th century CE, yet they were rare for a long time. In the 12th century the first schools appeared that taught "ninjutsu", the art of stealth. Shinobi saw widespread use in the "Sengoku Jidai", the 'Warring States Period', from the 15th century CE onward. The skills of the shinobi were often transferred from father to son. Most shinobi families came from the mountainous Iga and Koga provinces. When their number grew, they developed a kind of guild structure, dividing territories among them. The ruling samurai looked down on them, as they belonged to the lower classes and practiced tactics that were questionable to samurai. Nonetheless, shinobi were hired for their skills.
The shinobi were active in the Battle of Sekigahara, the Siege of Osaka and the Battle of Tennoji. In these battles and sieges they fought mostly as regular soldiers. But the real use of shinobi was in scouting, infiltration, sabotage, assassination and most of all spying. They were employed in smaller numbers or as individuals on numerous such missions, from which little evidence survives.
Shinobi training included exercises for physical fitness, climbing, swimming and sneaking. Knowledge of disguise, weapons, poisons and pyrotechnics was taught and also medicine. They learned how to distract guards, sneak into buildings and escape without being caught. Naturally, they preferred to evade combat, but if necessary did fight. In addition to normal weapons like swords and bows, the shinobi used an array of specialized ones. The used throwing darts and "shuriken", stars; "kusarigama", chain-and-sickle; "mikibishi", caltrops and several other types. Most weapons were smaller than their battlefield counterparts, both to suit combat in close quarters and to be hidden inside sticks or under clothing. In response, Japanese castles were equipped with traps, alarm bells and in the case of Nijo castle, squeaking floor boards.
At the end the Sengoku Jidai the warlord Oda Nobunaga clamped down hard on the shinobi. After some hard battles where he forced them to fight in the open. The shinobi guilds were destroyed, though small groups remained active. Tokugawa Ieyasu employed several, but after he unified Japan in 1603 CE, shinobi faded back into obscurity. Many myths have sprung up about their skills and organization, however these are based on little evidence. For example their black garb is a fantasy of modern re-enactors, derived from the artistic convention of portraying them in black to signal invisibility. In reality, shinobi mostly dressed in civilian clothes to disguise themselves.