Iraqi Shia Muslims belong to various ethnicities, although they all follow the Twelver sect, with the vast majority being Usuli and a small minority being Akhbari.

After the failed uprising, Mukhtar al-Thaqafi once again called for the establishment of an Alid caliphate and for retaliation for Husayn's killing, and took over Kufa in October 685.

[9] The 7th Twelver Imam Musa al-Kazim was repeatedly imprisoned in Baghdad and Basra at the orders of Abbasid caliphs al-Mansur, al-Hadi, al-Mahdi and Harun al-Rashid.

[14][15] Qizilbashism also had a presence among the Iraqi Turkmen, who continued their practices until the 1920s, when orthodox Twelver missionaries from Southern Iraq began to convert them.

Kufan followers of Mukhtar al-Thaqafi later formed the Kaysanite sect, who traced the line of Imamate to Muhammad ibn al-Hanafiyya.

The Hamdanids first emerged as governors of Mardin in 890 and Mosul in 905, and by 950 had expanded into most of Syria and western Iraq, informally forming a parallel authority to the one in Baghdad.

[21][22] During the 930s and 940s, the Hamdanids and the Buyids were in contest with another Shia, Abu Abdallah al-Baridi, an Iraqi tax-official who used the enormous wealth gained from tax farming to vie for control of the rump Abbasid Caliphate, temporarily holding Baghdad with brother twice.

During the 19th century, the Ottoman Empire instituted a policy of settling the semi-nomadic Sunni Arab tribes to create greater centralization in Iraq.

[29] The tribes adopted a sedentary agricultural life in the hinterlands of Najaf and Karbala, and frequently traded and interacted with the residents of the two cities.

[33] The Bani Sallama, Tayy and al-Soudan in the Mesopotamian Marshes were converted by the Musha'sha'iyyah dynasty, a heretical Isma'ili Shia tribal confederation founded by Muhammad ibn Falah which ruled the town of Hoveyzeh in Khuzestan from 1435 to 1924.

One of the eminent Shia mujtahideen, Ayatollah Mirza Muhammad Taqi al-Shirazi, then issued a fatwa "declaring that service in the British administration was unlawful".

[48] The revolt materialized in June 1920 and rapidly spread from Baghdad to the South, notably the town of Al-Rumaitha, where the Zawalim sheikh Shaalan Abu al-Jun was arrested and subsequently freed by his tribesmen.

[49] More Shia ulama, including Mirza Mahdi al-Shirazi, Mehdi Al-Khalissi and Muhammad Hasan Abi al-Mahasin displayed their support for the revolt, and encouraged the local population to take arms.

[54] For example, figures such as Saladin, Harun al-Rashid or Omar ibn al-Khattab who were venerated by Arab nationalists are viewed with suspicion in Shia folklore.

To counter the intellectual hold of the left, a group of clerics in Najaf created a movement that eventually evolved into the Dawa party.

[57] Abdul Salam Arif, president from the 1963 coup until his death in 1966, used derogatory terms in leadership meetings to describe Iraqi Shia and opposed his predecessor Abd al-Karim Qasim's policy of bringing all citizens into the regime regardless of ethnicity or religion.

[61] Subsequently, the regime banned annual Marad al-ras processions during the Mourning of Muharram in the shrine cities, where mass discontent had been evident in 1974 and 1975.

In 1977, tens of thousands of Dawa activists held the processions in defiance of the ban, leading to large-scale clashes known as the Safar Intifada that the regime quelled with the use of helicopter gunships.

The uprising spread within days to all of the largest Shia cities in southern Iraq: Amarah, Diwaniya, Hilla, Karbala, Kut, Nasiriyah and Samawah.

Many exiled Iraqi dissidents, including thousands of Iran-based Badr Brigades militants of SCIRI, crossed the borders and joined the rebellion.

Of the 200 mass graves the Iraqi Human Rights Ministry had registered between 2003 and 2006, the majority were in the South, including one believed to hold as many as 10,000 victims.

[full citation needed] During the 2006–2008 sectarian violence, tens to hundreds of thousands of people were killed (mainly Shia civilians) and at least 2.7 million were internally displaced.