When the last descendant of ali, the eleventh imam, disappeared in 830 c. e., many shia became twelvers, believing that the twelfth imam would

That he would return to be among the people in order to bring justice and peace.

Explanation:

Such a belief  plus the belief of the right of Ali as the rightful successor of prophet Muhammad as the leader of all Muslims, is one of the main differences between Sunni Islam and Shi´ia Islam, differences that have proved to be irreconcilable so far. The Twelfth Imam disappeared in the 9th century.

the crusades are one of the most significant events in the history of europe and the middle east.   they were a series of religious wars carried out by christian crusaders from europe during the timeframe of the middle ages.   beginning in 1095 ce, the crusades saw european knights and noblemen travel to the middle east in an attempt to capture the holy land away from muslim people that had controlled the region for the previous centuries.   the term crusade means ‘cross’.   therefore, the europeans that became crusaders viewed themselves as ‘taking up the cross’.   in fact, many of the crusaders wore crosses on their clothing and armor as they made their pilgrimage to the holy land.

explanation: