Hattori Hanzō (服部 半蔵, Hattori Hanzō), also known with the first name Masanari or Masashige (正成), born in 1541 or 1542 and died on December 23, 1596, was a famous Japanese ninja and samurai. His ferocity in battle earned him the nickname Oni Hanzō (鬼半蔵, Hanzō the Demon).
Hanzō was the son of Hattori Yasunaga. Born a vassal of the Matsudaira clan, then of the Tokugawa clan, Hanzō Hattori proved to be one of the best and most loyal servants of Tokugawa Ieyasu. He fought his first battle at the age of 16, during a night attack on Udo Castle.
In 1562, Hanzō participated under Ieyasu's orders in the siege of Kaminogō castle guarded by Udono Nagamochi, general of the Imagawa. With this capture, he obtains many members of the family of a relative of Imagawa Ujizane.
This capture allows him to recover Ieyasu's wife and son, who were being held hostage, in exchange for the prisoners. Hanzō also fought during the battle of Anegawa in 1570 and then the battle of Mikata-Ga-Hara in 1572.
In 1579, Tsukiyama-dono, Ieyasu's wife, along with his eldest son Tokugawa Nobuyasu, were accused of conspiring with the Takeda clan by Oda Nobunaga and held hostage. Acting out of complacency toward Nobunaga, Ieyasu ordered his son to commit seppuku, even though he was married to Tokuhime, Nobunaga's eldest daughter.
He then called upon Hanzō to assist him as kaishakunin (the person appointed to perform the beheading and end the suffering of the condemned). However, Hanzō refused to allow his blade to be impregnated with the blood of his own lord. Ieyasu was all the more appreciative of his loyalty, and is quoted as saying, "Even a demon can shed tears."
Nobuyasu was forced to commit suicide anyway, and Tsukiyama-dono was executed. It seems that Ieyasu deeply regretted this act afterwards.
Hanzō is said to have planned a brilliant defense of the ninja lands of Iga province during the Iga War of Tenshō in 1579 against Oda Nobukatsu, Nobunaga's second son. In 1581, he fought valiantly, in a desperate effort, to prevent Iga from being eliminated by forces under the command of Nobunaga himself.
His most memorable contribution, however, was after Nobunaga's death in the Honnō-ji incident in 1582. At that time, Ieyasu and his ninjas were stationed near Osaka, and learned of Nobunaga's death just in time to flee and avoid the troops of the traitorous assassin Akechi Mitsuhide.
However, they were not yet safe: Mikawa was still far away and Akechi's men could block the roads. Hanzō proposed the idea of going to Iga, where there were ninjas rallying to his cause. In addition, Ieyasu had helped the survivors of Nobunaga's invasion in 1580, and those who remembered this would be willing to help the group.
General Honda Tadakatsu sent Hanzō, and as expected, Iga's men agreed to help, guide, and even offer an escort. Eventually, Ieyasu was able to return safely to Mikawa. Hanzō's reputation as a ninja leader commanding 200 of Iga's men then assumed legendary proportions.
Nobukimi Anayama, on the other hand, who had insisted on taking a different route, claiming that young Hanzō had no idea of the detour he was imposing on them, was not so lucky. Captured by men of his former daimyo Takeda Katsuyori, he was beheaded.
Historical sources say that he lived the last years of his life as a monk, under the name Sainen, and built the Sainenji temple, renamed as such after his death and mainly built to commemorate Nobuyasu, Ieyasu's eldest son.
Hanzō was known as an expert tactician and a master of yari fighting. Accounts of his exploits often attributed to him various supernatural powers, such as teleportation, psychokinesis, and precognition, which contributed greatly to his prominence in popular culture.
In 1596, Hanzō is said to have died while on a mission, tracking the notorious ninja Fūma Kotarō. His ships became trapped with the tide and Kotarō's troops set fire to the canal, finishing off his warrior "rival."
Hanzō was succeeded by his son, Hattori Masanari, who was appointed Iwami-no-kami by Ieyasu. He succeeded his father, less brilliantly it seems, at the head of 200 men from the famous Iga-ryū, in the Yotsuya district of Edo. The Hanzōmon ("Hanzō Gate") of Edo Castle got its name from the fact that it was near the residence of the Hattori clan.