"47 Ronin" is a rather famous work. It is often portrayed in Japanese culture in manga, anime, and many popular movies. Some of these movies have made it to the US, and their derivatives, such as "47 Ronin", "13 Assassins" and "Last Knights", etc.
Allyn excellent translation tells the story of the incident. In the 1700s, after the Shogun had established complete control, a rural Lord, Lord Asano Naganori, felt insulted by the Shogun's Master of Ceremony, Lord Kira Kozuke-no-suke Yoshihisa, and attacked him. The fallout resulted in the shame of his entire clan and their dissolution.
But, not all of Lord Asano's Samurai would go quietly into the night. Led by Oichi, these 47 remaining Samurai, now Ronin, enact a plan to seek revenge on Lord Kira and avenge their Lord. Their loyalty to the samurai code of honor made them heroes.
This is the gist of the story. But the actual history of the events is somewhat different. This story was first popularized by a kabuki theatre that was called "Kanadehon Chushingura" (The Treasure House of the Loyal Retainers). This became a mass sensation.
Yet, much like English history that was warped by Shakespeare, this "story" of the events portrays Lord Kira as an arch-villain. Lord Asano was the hero. In that version of "history" the evil and greedy Lord Kira was trying to squeeze money out of the honorable Lord Asano. The truth is far more likely a situation where Lord Kira, as The Shogun's Master of Ceremony, is expected to receive ceremonial gifts as this is a long-standing Japanese tradition. Likely the rural, and old-school, Lord Asano, shocked and disconcerted by the effete manners of the Shogun's Court, was rebuked by Lord Kira for his lack of protocol and manners. Lord Asano, in a huff, draws his sword and injures Lord Kira. Except, Lord Asano drew a weapon in the Shogun's palace and struck the Shogun's Master of Ceremony. Thus, he was forced to commit seppuku and his entire clan's holding and noble status liquidated.
Those being the events, I find some issues with the ethic behind the 47 Ronin. They speak of following samurai code and honor and I completely understand BUT as a Samurai in the time of the Shogun, you are breaking the law by seeking revenge and you are questioning the judgement of the Shogun by your actions (it was the Shogun who ordered Lord Asano's death, not Lord Kira) which, by law and the samurai code, means you are doing a dishonorable act. Thus while the justification for the act may have been tenuous, the sheer audacity of the 47 coupled with Lord Kira's fall from grace for corruption led to the events of the book and resulted in them being treated as "honorable" by the Shogun and allowed honorable seppuku themselves. This is why they became folk heroes.
Thus this is a great tale of revenge by a band of loyal warriors to avenge their Lord's wrongful death. A wonderful story of the Shogunate period.