or Second Hanzō, nicknamed , was a famous Ninja of the Sengoku era, who served the Tokugawa clan as a ninja, credited with saving the life of Tokugawa Ieyasu and then helping him to become the ruler of united Japan. He is often a subject of varied portrayal in modern popular culture. Hanzō was known as an expert tactician and a master of sword fighting. Early life Born the son of (first Hanzō), a minor samurai in the service of the Matsudaira (later Tokugawa) clan. His birth name is , and he became known as the Second Hanzō. He would later earn the nickname because of the fearless tactics he displayed in his operations; this moniker also distinguished him from Watanabe Hanzo (Watanabe Moritsuna), who is nicknamed . Though Hanzō was born in Mikawa Province (now Iga-chō, Okazaki, Aichi), he often returned to Iga Province, home of the Hattori family. At the age of 16, his first battle was a night time attack during the siege of Udo Castle (1557). At the time, he commanded seventy Iga ninja. Service under Ieyasu Hanzo had a great contribution to Tokugawa Ieyasu's rise to power, helping the future Shogun bring down the Imagawa clan. After Imagawa Ujizane had held Ieyasu's wife and son as hostages in 1561, Hanzo made a successful hostage rescue of Tokugawa's family at Kaminogo castle in 1562<ref>Tools and Techniques (2009), p. 94</ref> and went on to lay siege to Kakegawa castle in 1569 against the Imagawa clan. He served with distinction at the battles of Anegawa in 1570 and Mikatagahara in 1572. According to the Kansei Chōshū Shokafu, a genealogy of major samurai completed in 1812 by the Tokugawa shogunate, Hattori Hanzō rendered meritorious service during the Battle of Mikatagahara and became commander of an Iga unit consisting of one hundred fifty men. He captured a Takeda spy named Chikuan, and when Takeda's troops invaded Totomi, Hanzō counterattacked with only thirty warriors at the Tenryū River. His most valuable contribution came in 1582 following Oda Nobunaga's death, when he led the future shōgun Tokugawa Ieyasu to safety in Mikawa Province across Iga territory with the help of remnants of the local Iga-ryū ji-samurai clansAndrew Adams, Ninja: The Invisible Assassins (1970), p. 43 as well as Kōga-ryū the neighboring local samurai families in the nearby Koka region.Haha Lung, Ninja Shadowhand, The Art of Invisibility (2004), p. 50 Hanzo was principal