Caliphate

Lady Zahra (as) herself made a will demanding her grave to remain hidden in order to show her disapproval and objection to those who usurped caliphate after her father.  

Regarding the ambiguity in the martyrdom date of Lady Fatima, Islamic scholars have mentioned different causes. Some maintain that the ambiguity originates from a misunderstanding caused by the way scribes registered the martyrdom date of Fatima. 

Muslims in medina did not support Imam Ali (A) against usurpers as if they forgot the word of the Prophet (P) about Ali (A) and his sermon in Ghadir. Several protests have been registered by him indicating that had Imam had real and sufficient supporter he would have waged a war against usurpers.

Imam Ali (A) was appointed as the Prophet's successor in Ghadir Khumm, but some of the companions opposed him due to some reasons that are going to be mentioned.

The difference between Shia and Sunni refers to the caliphate or succession to the Prophet (p). Shia believes that the Imam must be appointed by Allah (SWT) like the prophets and he has the same responsibilities as the Prophet (p) had, except there is no revelation. Sunni believes that Muslims or Muslim community consensus should elect the caliph.

The historical circumstances prove that a few dominant Emigrants disputed over the caliphate. That is why the Helpers hurried to Saqifa, because they tried to negate the Emigrants agreement. Perhaps, these Emigrant companions were not sure about the successor of the Prophet (PBUH), but they were firm to deprive Imam Ali (PBUH) of his right.