Shia–Sunni relations
After the death of Muhammad in 632, a group of Muslims, who would come to be known as the Shias, believed that his successor should have been Ali ibn Abi Talib. Abu Bakr was already the first caliph, so the Sunnis were the Muslims at the time while the Shias were a new sect who favored Ali. This dispute spread across various parts of the Muslim world, which eventually led to the Battle of the Camel and Battle of Siffin. Sectarianism based on this historic dispute intensified greatly after the Battle of Karbala. During the battle, Husayn ibn Ali and some of his close partisans, including members and children of Muhammad's household (Ahl al-Bayt), were thought by the Shias to have been killed by the ruling Umayyad Caliph Yazid I. Although Yazid was not responsible, the outcry for revenge divided the early Islamic community, albeit disproportionately, into the Sunni and the Shia. This is known today as the Islamic schism.[1]
The present demographic breakdown between the two denominations is difficult to assess and varies by source, with most approximations stating that roughly 90% of the world's Muslims are Sunni and 10% are Shia; with about 85% of Shias belonging to the Twelver tradition, and the rest divided between other small groups.[2] Sunnis are a majority in almost all Muslim communities around the world. Shia make up the majority of the citizen population in Iran, Iraq, and Azerbaijan, as well as being a minority in Pakistan, Lebanon, Saudi Arabia, Syria, Yemen, Nigeria, Afghanistan, Chad, Turkey, Bahrain and Kuwait.[13][14] Today there are differences in religious practice, traditions, and customs, often related to jurisprudence. Although all Muslim groups consider the Quran to be divine, Sunni and Shia have different opinions on hadith.
In recent years, Sunni–Shia relations, commonly termed the Sunni–Shia divide, have been increasingly marked by conflict.[15] The aftermath of the 1979 Iranian Revolution, which reconfigured Iran into a theocratic Islamic republic governed by high-ranking Shia clerics, had far-reaching consequences across the Muslim world. The Iraq war further influenced regional power dynamics, solidifying Shi'ites as the predominant force in Iraq. Iran's ascent as a regional power in the Middle East, along with shifts in politics and demographics in Lebanon, heightened concerns among Sunni nations about potential challenges to Sunni–Arab hegemony.[16] Recent years have witnessed the Iran–Saudi Arabia proxy conflict, as well as sectarian violence from Pakistan to Yemen, which became a major element of friction throughout the Middle East and South Asia.[17][18] Tensions between communities have intensified during power struggles, such as the Bahraini uprising, the Iraqi Civil War, the Syrian Civil War,[19][20][21] as well as the War in Iraq (2013–2017), during which the self-styled Islamic State of Iraq and Syria launched a persecution of Shia.
The declaration of Shi'ism as the state religion of the realm by Shah Ismail – 1501 Tabriz central mosque.
Monument commemorating the Battle of Chaldiran, which was fought between the Sunni Ottoman Empire and the Shia Safavid Empire.
