Battle of Mikatagahara
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.