Ashura is a day of mourning and grief in the calendar of all Shi’a Muslims around the globe. This significant milestone commemorates the martyrdom of the Prophet Muhammad’s grandson, Husayn ibn Ali, at the Battle of Karbala in 680 CE. This is the first encyclopedic dictionary in English which defines both for laymen as well as scholars the names and concepts associated with this historic day and the events that happened before and after it. This book is a must-read for anyone who wants to understand this epoch-making event which, to this day, continues to influence not only the Shi’a community but also other faith groups who venerate and idolise Husayn as the martyr who laid down his life to speak truth to power and as the heroic figure who redefined the paradigm of the struggle against tyranny and oppression.