Tenth day of the Muslim month of Muharram. Commemoration of the martyrdom in 680 of Husayn, Muhammad's grandson and the third imam of Shii Islam. Shii communities annually reenact the tragedy in a passion play, including self-mortification and displays of sorrow and remorse intended to unite them in Husayn's suffering and death as an aid to salvation on the Day of Judgment. Shii communities experiencing deprivation, humiliation, or abuse today understand Husayn's martyrdom as a paradigm for the struggle against injustice, tyranny, and oppression. Became a major symbol and slogan during the Iranian Islamic revolution, during the Iran-Iraq war (1980–88), and in Lebanon.