We hear about the Iraq war everyday and most of the time we hear about Shia and Sunni, the only thing we know about them for certain is they are Muslims, beyond that we have some vague idea. But the differences in these religious sects is one of the reasons for the majority of problems in Iraq. An understanding would help.
Image credit: Indi.ca article "Who Will Rule Iraq? (Iraqi Power Players)"
Like Christianity, Islam is home to a spectrum of sects espousing different beliefs and practices. And just as Christianity can be divided into two large groups - Catholic and Protestant - from which other subsects have emerged, so too with Islam: Shia and Sunni.
Unlike Christianity, whose major split wouldn’t occur for nearly sixteen centuries, Islam split almost immediately after the death of its founder, the Prophet Muhammad (circa 570 - 632 CE).
Prophet Muhammad wanted to unite everyone in that region under one umbrella of Muslim religion but immediately after his death on June 8, 632, the religion divided into sub groups. After the prophet's death, his followers met at Medina and proclaimed Abu Bakr as their Caliph or political leader. The claim came because of Abu Bakr close relationship with Muhammad, and also because of the fact Abu Bakr was asked specifically by Prophet Mohammad to lead the prayers when he was too ill to do so himself. Those who recognize Abu Bakr and his three immediate successors, called the Four Rightly Guided Caliphs, are referred as Sunni Muslims and they account 90% of all Muslims worldwide.
However, one group of followers, refused to accept Abu Bakr, this group called Rafidi (Refusers) supported the claim of Ali ibn Abi Talib, Prophet Mohammad's cousin and son-in-law. They base the claim on a sermon by the Prophet had given at Ghadir Khum, in which Mohammad referred to Ali as mawla, which some translate it as "master". Ali's followers called themselves Shiat Ali means the Party of Ali, they are called today as Shia. To the Sunnis, Ali is the last of the Four Rightly Guided Caliphs, for the Shia's he is the first. And also for the Shias, Ali is the first Imam, the word the Shia Muslims refer to the person chosen as the leader of the faithful.
Both Sunnis and the Shias revere the Koran, however accept different hadiths (oral traditions), so their religious laws are different. Many Shias, for example, allow temporary marriage. Shias also recognize esteemed imams as supreme expert on Islamic law, called Ayatollahs or, for the really big guys, Grand Ayatollahs.
Where are they distributed, they are all dispersed in various countries, but the Shias are a majority in only two countries, Iraq and Iran. The author says, the violence between the two have been widely talked about and assumed it has been raging for a long time. But in reality most of the violence between them arose in the last 50 years, and can be attributed directly or indirectly to Saddam Hussein, a Sunni. He was not even religious but he was the major cause for the differences between the two.
The Map in the picture shows how the various sects are distributed, in the future there is a possibility the country may be divided into separate countries like the picture shown, because there doesn't seem to be any reconciliation between the two.
To read more about the differences or about these two religions click here.