Hattori Hanzō (服部半蔵)(1541-1596), also known as Masanari and as Masashige, was the son of a certain Hattori Yasunaga. Born a vassal of the Matsudaira (later Tokugawa) clan, Hanzo, who would earn the nickname Devil Hanzō, served Tokugawa Ieyasu loyally and usefully. His nickname was not only to pay homage to his skills but also to distinguish him from another Tokugawa ninja, Watanabe Hanzō. Hattori, who fought his first battle at the age of 16, went on to serve at the battles of Anegawa (1570) and Mikatagahara (1572), but his most valuable contribution came in 1582, following Oda Nobunaga's death.

At that time, Ieyasu and his retainers had been staying near Osaka and learned of the assassination only just in time to avoid being detained by Akechi Mitsuhide's troops. But they were not safe yet. Mikawa was still a long way away, and Akechi's men would be combing the roads for them. At this point, Hanzō suggested that they take a route through Iga Province, as he had ties with the samurai there. In addition, Ieyasu had sheltered survivors from Nobunaga's bloody invasion of that province in 1580 and those who knew of this would certainly be well disposed to offer assistance. Honda Tadakatsu sent Hanzō on ahead, and, as hoped, the Iga men agreed not only to guide them along back roads, but also to provide them with an escort. At length, Ieyasu and his band returned to Mikawa safely. The same could not be said for Anayama Beisetsu, a recent Tokugawa addition who had insisted on taking a different route.

Hanzō was succeded by his son, Masanari, who would be given the title Iwami-no-Kami and whose men would act as the guards of Edo Castle. Hanzō's reputation as a ninja leader who commanded a 200-man strong unit of Iga men has grown to legendary proportions.

To this day, artifacts of Hanzo's legacy remain; the Hanzo-mon subway line in Tokyo is named after him.

Detailed biography of Hattori Hanzo (http://www.skhquest.com/articles/HanzoHattori.aspx)

Hanzō in Fiction

Hattori Hanzō is very widely depicted in games as an especially powerful and important ninja. In Kill Bill he appears as the maker of the best swords in the world.

In addition, Hanzō frequently appears in jidaigeki. Actor Shin'ichi (Sonny) Chiba played the role in the television series Kage no Gundan. Many films, specials and series on the life and times of Tokugawa Ieyasu depict the events detailed above. He is also featured prominently in SNK Playmore's video game series: Samurai Shodown.