The majority of Shi’ites are Twelvers. They were originally the same group of friends and supporters of Ali who, after the death of the Prophet, in order to defend the right of the Household of the Prophet in the question of the caliphate and religious authority, began to criticize and protest against prevalent views and separated from the majority of the people.
During the caliphate of the "rightly-guided caliphs" (11/632-35/656) the Shi’ites were under a certain amount of pressure which became much greater during the Umayyad Caliphate (40/661-132/750) when they were no longer protected in any way against destruction of their lives and property. Yet the greater the pressure placed upon them, the firmer they became in their belief. They especially benefited from their being oppressed in spreading their beliefs and teachings.
From the middle of the 2nd/8th century when the Abbasid caliphs established their dynasty, Shi’ism was able to gain a mew life as a result of the languid and weak state prevailing at that time. Soon, however, conditions became difficult once again and until the end of the 3rd/9th century became ever more stringent. At the beginning of the 4th/10th century, with the rise of the influential Buyids, who were Shi’ites, Shi’ism gained power and became more or less free to carry out its activities.
It began to carry out scientific and scholarly debates and continued in this manner until the end of the 5th/11th century. At the beginning of the 7th/13th century when the Mongol invasion began, as a result of the general involvement in war and chaos and the continuation of the Crusades, the different Islamic governments did not put too great a pressure upon the Shi’ites. Moreover, the conversion to Shi’ism of some Mongol rulers in Persia and the rule of the Sadat-i Mar’ashi (who were Shi’ites) in Mazandaran were instrumental in the spread of the power and territory of Shi’ism. They made the presence of large concentrations of Shi’ite population in Persia and other Muslim lands felt more than ever before. This situation continued through the 9th/15th century
Shia Islam and the Caliphate of Imam Ali
