Benkei as portrayed in Kabuki plays.

Saito Musashibo Benkei (西塔武蔵坊弁慶, 1155_1189), popularly called "Benkei" (弁慶), was a Japanese fighting monk who served Minamoto no Yoshitsune. He is regarded as a man of great strength and loyalty, one of the favourite subjects of Japanese folklore. So much of his life has been embellished and distorted by Kabuki and Noh drama, that most of it cannot be distinguished from legend.

Stories about Benkei's birth vary considerably. One tells how his father was the head of a temple shrine who had raped his mother, the daughter of a blacksmith. Another sees him as the offspring of a temple god. Many give him the attributes of a demon, a monster child with wild hair and long teeth. In his youth Benkei may have been called Oniwaka (鬼若) - the "devil's child".

He joined the cloister at an early age and travelled widely among the monasteries of Japan. During this period, the Buddhist monasteries of Japan were important centres of administration and culture, but also military powers in their own right. Like many other monks, Benkei was probably trained in warfare. At the age of seventeen, he was said to have been over two metres tall. At this point he left the Buddhist church and joined the Yamabushi, a sect of wandering bandit monks, who were recognised by their black caps. Images of Benkei on Japanese prints often show him wearing this cap.

Benkei is said to have posted himself at Gojyo Bridge in Kyoto, where he deprived every swordholder who passed of his weapon, eventually collecting 999 swords. On his 1000th duel, Benkei was defeated by Minamoto Yoshitsune, a son of the warlord Minamoto no Yoshitomo. Henceforth, he became a retainer of Yoshitsune and fought with him in the Genpei War against the Taira clan. Yoshitsune is credited with most of the Minamoto clan's successes against the Taira, especially the final naval battle of Dannoura. After their ultimate triumph, however, Yoshitsune's elder brother Minamoto Yoritomo, turned against him.

During the two year ordeal which followed, Benkei accompanied Yoshitsune as an outlaw. In the end they were encircled in the castle of Takadachi. Legend recounts how Benkei, pierced by arrows, fought to the bloody end, and died standing on his feet.

Undoubtedly, it is Benkei's loyalty and honour which makes him most attractive in Japanese folklore. One Kabuki play places Benkei in a moral dilemma between lying and protecting his lord to crossing a bridge. The critical moment of the drama is its climax, where the monk realises his situation and vows to do what he must.