In 1701, one of the feudal lords in attendance to the shogun in the Edo castle was called upon to take part in a formal ceremony. He was to have been instructed by the chief chamberlain, who, perhaps dissatisfied with his tip, insulted the lord he should have been teaching. This resulted in the drawing of weapons in the castle, a proscribed act and the forced suicide of the unfortunate lord.
Upon hearing of the event, a number of the faithful retainers decided to avenge the death of their lord. After a year of planing, these "ronin," masterless samurai all, took revenge, sought out the chamberlain and killed him.
Despite the fact that one of the stipulations of the samurai code was that one should not live under the same heaven nor tread the same earth as the enemy of one's lord, the shogunate had made revenge a capital offense. This being so, the authorities decided they had no alternative but to order the suicide of all the ronin. This was accomplished despite petitions by the populace to the shogun and the popular wish that the ronin be spared and their heroism, as it was seen, validated.