The Islamic calendar is based on the cycle of 12 lunar months and the first month, Muharram, in this Islamic year of 1433 began two weeks ago at the end of November. The 10th day of Muharram, known as Ashura, is significant to Muslims and how it is commemorated sets them apart in a feud that goes back to the founding years of Islam.

This feud remains literally explosive and every Ashura, somewhere in the Arab-Muslim world — as happened this week in Kabul — fanatics among the majority Sunni Muslims set forth to kill members of the minority Shia Muslims.

Hussain -- Karbala battle
Hussein bin Ali as he addressed Yazid's army.

This feud’s origin lies in an immense crime. It is the murder of Husain, the grandson of Muhammad, the prophet of Islam, and born to his favourite daughter Fatima, married to Ali, his cousin. Those responsible for this crime eliminated any claim on the part of Ali, and his sons — Hasan and Husain — to succeed Muhammad in leading the newly united tribes of Arabia under the flag of Islam.

The struggle over Muhammad’s succession began as his health failed and before his death in 632, the year 10 in the Islamic calendar. It divided the first generation of Muslims, led to wars, assassinations, and the murder of Ali and Hasan.

In 680, the year 61 in the Islamic calendar, Husain was invited by the people of Kufa in Iraq to join them, assume leadership among Muslims that was his by lineage, and represent the righteous order subverted by the existing ruler in Damascus. Husain responded and with family and friends, around 100 in number, departed Medina for Kufa. But some 64 km ahead of the destination at Karbala, Husain’s caravan was blocked by an army under orders from Damascus. Husain was ordered to surrender and recognize Yazid, son of Muawiya and grandson of Abu Sufyan — the most bitter foe of Muhammad — as the caliph in Damascus. Husain was trapped. He chose to resist. Fighting broke out, and the male companions of Husain were killed.

Then finally on Ashura, Yazid’s army bore down upon Husain and decapitated him in the field of Karbala. His body was trampled upon by the cavalry that rushed him, his head removed and hoisted upon a spear, the female members of his family humiliated and bound as slaves, and taken, along with Husain’s head as a trophy, to Damascus.

, in a recently published book After the Prophet: The Epic Story of the Shia-Sunni Split (2010), narrates this blood-chilling history. It should be read widely to understand the feud that remains explosive into our time among Muslims.

Hazleton’s narrative is based entirely on the most reliable accounts of the events by Muslim historians from the first and second century of the Islamic calendar. The most notable and respected of these historians is the man simply known as al-Tabari (838-923), and his voluminous account of the earliest years of Arab-Muslim history are the primary source of all subsequent writings about Islam’s early years.

For the vast majority of Muslims this history has been air-brushed, and there can be little understanding of Arab-Muslim politics without fully grasping what occurred on Ashura more than 13 centuries ago.