Ishikawa Goemon was a Japanese bandit from the late 16th century, in the Edo era, who has reached legendary reknown. Originally known as a thief that was reportedly put to death by boiling oil in 1594, he has been the subject of countless plays, novels, movies, and computer games. The legend that has grown around him is that he was a Robin Hood for the times, stealing from the rich (particularly the cruel Daimyo, Toyotomi Hideyoshi), and giving to the poor. There are many stories about him, and they tend to be dramatically different. According to some, he was a "ninja", trained by the ninja master Momochi Sandayu. According to others he was a samurai, formerly known as Sanada Kuranoshin, who became a ronin.
The legend of his death is that he was captured during an assassination attempt. He was sneaking in to Fushimi castle, where the Daimyo lived, with the purpose of killing the ruler in his sleep. Toyotomi Hideyoshi was not a popular Daimyo, apparently being a very vicious tyrant who ruled his people mercilessly. The Daimyo had a magic incense burner that warned him of the intruder, and guards captured him quickly. He and his family were put to death, placed in a cauldron of boiling oil. However, there are stories that Ishikara never attempted to assassinate the Daimyo, and that it was instead a plot, a coup attempt by the military, which failed, and was blaimed on him. There are stories that claim that he was never actually caught, and the story of the boiling in oil was created by the Daimyo to save face.
The history of Ishikawa Goemon has become clouded by story-tellers, legend, and antiquity. What we do know, is that he has become a very popular character in Japanese culture. Ishikawa Goemon is used as an archetype, and used in stories he could not possibly have been in, anachronistically. In this manner, he is similar to Miyamoto Musashi. There is a kensei (sword saint) in the Lupin series who uses the moniker, and there are many "ninja movies" in which he is the lead character. Something about his persona inspires the imagination, and he is a regularly recurring character in Japanese entertainment.