Of the two, Sunni is the majority with 75%-90% muslims and Shiite the minority with 10%-20%. Although Shia and Sunni are both Muslim, and both believe in the core fundamentals such as the Five Pillars and Quran, they are greatly different from each other also. Between the two, there has been a lasting tension due to differing ideals. .
The conflict arose after the death of the Prophet Muhammad died in A.D. 632. Following the Prophet's death, his followers disagreed on the issue of who should become his succession or caliph (the chief Muslim civil and religious ruler). From this conflict arose two opposing ideals and groups. One group, currently known as Shiite or Shia, proposed the Prophet had intended the caliph to remain within the Prophet's bloodline and should be passed to Ali, the husband of the Prophet's daughter and Prophet's cousin. Due to this they admired Ali greatly, and supported him as the following Imam (an Islamic leadership position). The opposing group, currently known as Sunni's, insisted the prophet had left the issue to be dealt by them, and believed the following caliph should be selected by the people as in democracies. Nonetheless, ironically the Sunni's elected Abu Bakr, which happened to be the the Prophet's father in law, as the following Imam. Following this, unrest with the issue eventually led to a civil war known as the "Battle of Karbala" between Sunni and Shia for many years, resulting with a Sunni victory and Abu Bakr becoming the first Imam. To this day, following this beginning civil war, the lasting rivalry has continued. Recently in February 2009, Shia's from Saudi Arabia's outer eastern parts came to Medina, a city within central Arabia to give respect for the anniversary of the Prophet Muhammad's death, however, refused by the Sunni religious officers to partake because of differing belief in the ritual, brought Shia's to collide with the opposition resulting in various captured, wounded, and 3 dead Shia Muslims.
