as palace guards—have led some sources to define the oniwabanshū as "ninja". This portrayal is also common in later novels and jidaigeki. However, there is no written link between the earlier shinobi and the later oniwaban. Roles The ninja were stealth soldiers and mercenaries hired mostly by daimyōs. Their primary roles were those of espionage and sabotage, although assassinations were also attributed to ninja. Although they were considered the anti-samurai and were disdained by those belonging to the samurai class, they were necessary for warfare and were even employed by the samurai themselves to carry out operations that were forbidden by bushidō. In his Buke Myōmokushō, military historian Hanawa Hokinoichi writes of the ninja: Espionage Espionage was the chief role of the ninja. With the aid of disguises, the ninja gathered information on enemy terrain and building specifications, as well as obtaining passwords and communiques. The aforementioned supplement to the Nochi Kagami briefly describes the ninja's role in espionage: Later in history, the Kōga ninja would become regarded as agents of the Tokugawa bakufu, at a time when the bakufu used the ninja in an intelligence network to monitor regional daimyōs as well as the Imperial court. Sabotage Arson was the primary form of sabotage practiced by the ninja, who targeted castles and camps. The Tamon-in Nikki (16th century)—a diary written by abbot Eishun of Kōfuku-ji temple—describes an arson attack on a castle by men of the Iga clans. In 1558, Rokkaku Yoshikata employed a team of ninja to set fire to Sawayama Castle. A chūnin captain led a force of 48 ninja into the castle by means of deception. In a technique dubbed bakemono-jutsu ("ghost technique"), his men stole a lantern bearing the enemy's family crest (mon), and proceeded to make replicas with the same mon. By wielding these lanterns, they were allowed to enter the castle without a fight. Once inside, the ninja set fire to the castle, and Yoshitaka's army would later emerge victorious. The mercenary nature of the shinobi is demonstrated in another arson attack soon after the burning of Sawayama Castle. In 1561, commanders acting under Kizawa Nagamasa hired three Iga ninja of genin rank to assist the conquest of a fortress in Maibara. Rokkaku Yoshitaka, the same man who had hired Iga ninja just years earlier, was the fortress holder—and target of attack. The Asai Sandaiki writes of their plans: "We employed shinobi-no-mono of