7. The Assassination

Arguably one of the most impactful incidents in early Islamic history, the assassination of Uthman opened up a whole new chapter therein. It became the excuse for ensuing civil strife and the root of all the problems Imam Ali (as) had to deal with once he became caliph. Imam Ali (as) himself had warned that this assassination would have such repercussions, but it only fell on deaf ears.