The Islamic New Year is on the first day of Muharram, the first month in the lunar Islamic calendar, which differs from the Gregorian calendar.
A year lasts for about 354 days and consists of 12 months in the Islamic/Hijri calendar.
The Battle of Karbala (currently in Iraq) in the year 680 CE, which enabled Husayn ibn Ali, a grandson of the Prophet Muhammed, and his army to enter the city on the first day of the month.
The restriction of Husayn ibn Ali's access to water on the seventh day.
The death of Husayn ibn Ali and his clan (Ahl al-Bayt) on the 10th day of the month.