What is Ashura and how do Shia and Sunni Muslims observe it?
The day of Ashura is an important occasion in the Islamic calendar that carries a spiritual and historical significance for both Sunni and Shia Muslims.
For the Sunni majority, the day is marked with fasting and special prayers in mosques. For Shia Muslims, it marks the anniversary of the killing of the Prophet Muhammad's grandson Hussein during the Battle of Karbala, and is therefore a day of mourning.
Shia rites on the day include colourful plays re-enacting the battle's events, with the faithful taking on the role of Hussein and his followers as they took on Umayyad forces loyal to the Caliph Yazid I.
The battle took place in 680 CE and while it became one of the causes of the split between Shia and Sunni Muslims, it happened long before religious differences between Sunni and Shia factions had crystallised.
For example, Sunnis also revere Hussein and many also take a negative view of Yazid, who is often criticised for his impiety.
While some Sunni Muslims do take part in mourning ceremonies for Hussein, especially followers of Sufi traditions, the events are less intense than their Shia counterparts.
One controversial aspect of the Shia mourning of Hussein is the practice among some of self-flagellation, or tatbir. Many leading Shia Islamic jurists, including the late Iranian leader Ayatollah Khomeini, have either condemned the act or argued that it is redundant in the modern era, but a minority of religious figures continue to stress its importance, usually with the caveat that no harm occurs to those taking part in the ritual.
Middle East Eye takes a closer look at the day and how it is marked by Muslims.
What is Ashura?
For Muslims, Ashura marks the day God delivered the Israelites, led by the Prophet Musa (Moses), from the tyranny of Egypt's Pharaoh by parting the Red Sea, thus allowing them to cross safely.
The day is observed with a fast and religious ceremonies, including sermons and communal meals in Sunni communities.
For Shia Muslims, the significance of the day also stems from it being the anniversary of the death of Hussein, who is venerated as an Imam, or the rightful leader of the Muslim community.
Twelver Shias, as the name suggests, recognise 12 successors of the Prophet Muhammad who are descended from him through his daughter Fatima and cousin and son-in-law Ali, who is the first Imam.
Hussein is the third of these successors and the Battle of Karbala marks the climax of his attempts to acquire leadership of the Muslim community from the Umayyads under Yazid.
In a bloody confrontation near the river Euphrates in what is now Iraq, Hussein and most of his followers were killed.
For Shias, Hussein's martyrdom represents paying the ultimate price in the pursuit of justice and righteouness, and he is therefore mourned to this day at his shrine in Karbala, as well as in mourning ceremonies across the Muslim world.
The line of Imams would continue through Hussein's surviving son, also named Ali. For Twelvers, the line stops with the twelth Imam, Muhammad al-Mahdi, who in Shia tradition disappeared into occultation and will return to precipitate the Day of Judgement.
When is Ashura?
Ashura is marked on the tenth day of Muharram, the first month of the Islamic lunar calendar, widely considered to be one of the holiest months in Islam.
Ashura falls on either 17 and 18 August in the Gregorian calendar, depending on the method of moon sighting used to determine the start of Muharram.
Why is it called Ashura?
"Ashura" comes from the Arabic word for the number ten, and the word Muharram comes from the Arabic word haram, meaning forbidden.
According to Islamic tradition, the month of Muharram was one of the most sacred months of the calendar, during which warfare was forbidden.
What is the religious significance?
Muslims fasting on the day of Ashura believe that God will forgive their sins from the previous year.
According to the Quran, God then commanded Moses to strike the sea with his staff, causing the sea to be parted.
Moses then started fasting on the day of Ashura as a form of worship and gratitude to God for saving himself and his followers.
The Prophet Muhammad encouraged Muslims to fast on the ninth of Muharram as well as the tenth, in order to differentiate Muslims from other faiths. While the fast is optional, many Muslims choose to observe it.
How is it marked by Shia Muslims?
Shia preachers will deliver sermons and recount the history of the Battle of Karbala. Some will also recite poetry relating to the life of Hussain, highlighting his virtues.
In many parts of Iraq and Iran, large public plays, marches and processions are held in front of thousands of people who gather to mourn and commemorate the event.
The "passion plays" are meant to highlight the significance of Hussein's sacrifice and evoke the emotional fervour needed to pursue the cause of justice.
Some take part in tatbir, which is banned in some counties but still takes place during Ashura. The use of blades, chains and other items to beat oneself symbolises sacrifice and struggle.
As previously mentioned, the practice is frowned upon by many clerics and many worshippers choose to mourn in alternative ways, such as by donating blood.
During the period of Muharram, Shia worshippers will often wear black as a symbol of mourning and sadness. Many will take this time as an opportunity to derive lessons from Hussein's life.
This article is available in French on Middle East Eye French edition.