Within six years of Husayn's brother's death...

Within six years of Husayn's brother's death, Mu'awiya started to openly call upon people to swear allegiance to his son Yazid, and people met his desire willingly or unwillingly. Imam Husayn [a.s.] numbered among the five men who alone refused to pledge themselves to Yazid. During the four years left to his life after securing allegiance for his son, Mu'awiya was unable to dissuade Imam Husayn [a.s.] from his firm opposition to such a system of rule.

If the caliphate was to be based on heredity, then none other than the Prophet's grandson and nearest surviving kin was more suitable. And if the right to rule was to be given on the basis of piety and learning, then to whom else other than Husayn [a.s.] - proven to be possessed of untainted wisdom, complete knowledge of Islamic law, piety and devotion of the highest degree - could this position be rightfully apportioned.

In the month of Rajab in the sixtieth year after Hijrah, the Bani Hashim were confronted with the caliphate of Yazid. Yazid did not have the forbearance of his father, and was not content to let Husayn [a.s.] stay in Medina in peace. The day after his father's death he wrote to Walid ibn 'Utba ibn Abu Sufyan, then governor of Medina, asking him to pursue Imam Husayn [a.s.], Abdullah ibn Umar, and Abdullah ibn Zubayr, and compel them to swear allegiance to him. Again Imam Husayn [a.s.] refused.

He decided to leave Medina, and, at the behest of other oppressed people, to go to Kufa where, he had been led to believe, there were many who wished to combat the tyrannical rule of the transgressing Bani Umayya and see to it that pure enlightened leadership of Muslims prevailed instead. Previous…