Husayn Mosque in Karbala, Iraq

Karbala (also spelled Kerbala or Kerbela) is a city in south-central Iraq, about 100km southwest of Baghdad. It is one of the holiest cities in Shi'a Islam, after Mecca, Medina, and Najaf.
Karbala is important because it is the site of the Shrine of Imam Husayn (also spelled Imam Hussayn or Imam Hussain), the grandson of the Prophet Muhammad and a much-revered Shi'a martyr. It is also home to the Shrine of Imam Abbas, Husayn's loyal half-brother.
After the death of the Prophet Muhammad in 632 AD, a conflict broke out over who should succeed him as leader of Islam. Some (later called the Shi'ites) said it should be the Prophet's descendents, while others (later called the Sunnis) argued that the community should choose a leader. As in all conflicts the matter was complex, but this was the basic difference that led to the separation between Shi'a and Sunni Islam that has endured to this day.
During this conflict, Imam Husayn was martyred at Karbala along with many followers in the Battle of Karbala in 680 AD. Husayn's tomb became a place of pilgrimage immediately after his murder. Extreme devotees even argued that a pilgrimage to Karbala was equal to the Hajj. Then as now, the death of Husayn was regarded as a powerful symbol for religious suffering and liberation from oppression.
A mosque was built over Husayn's tomb in 684 AD, and a successon of mosques have been built and destroyed on the site to this day. The original mosque was enlarged with another dome in 749 but was destroyed in 787. In 977, a sepulchre for Husayn's tomb was constructed of teak wood. The present mosque was built in the 11th century, with extensive reconstruction of the walls and dome in the 14th century.
Sunni rulers, among them Saddam Hussein, have regarded the themes of Karbala and Ashura as a potential threat and banned pilgrimages several times and even destroyed the shrines (which have always been rebuilt). In 1991, the richly endowed shrines of Karbala were plundered and damaged by the Iraqi army. After the city rebelled against Saddam Hussein, 32 mosques, 10 religious schools, and 66 prayer halls were brutally destroyed.
Even with Saddam removed from power, Karbala has continued to be a focus of sectarian conflict. The 2004 Shi'a pilgrimage to Karbala, the second since Hussein was removed from power in Iraq, was marred by bomb attacks that killed and wounded hundreds.