He had especially told Yazid in his last will that if Husayn...

He had especially told Yazid in his last will that if Husayn refused to pay allegiance he should pass over it in silence and overlook the matter, for he had understood correctly the disastrous consequences which would follow if the issue were to be pressed. But because of his egoism and recklessness, Yazid neglected his father's advice and immediately after the death of his father ordered the governor of Medina either to force a pledge of allegiance from Imam Husayn or send his head to Damascus.

After the governor of Medina informed Imam Husayn of this demand, the Imam, in order to think over the question, asked for a delay and overnight started with his family toward Mecca. He sought refuge in the sanctuary of God which in Islam is the official place of refuge and security. This event occurred toward the end of the month of Rajab and the beginning of Sha'ban of 60 A.H. For nearly four months Imam Husayn stayed in Mecca in refuge. This news spread throughout the Islamic world.

On the one hand many people who were tired of the iniquities of Mu'awiyah's rule and were even more dissatisfied when Yazid became caliph, corresponded with Imam Husayn and expressed their sympathy for him. On the other hand a flood of letters began to flow, especially from Iraq and particularly the city of Kufa, inviting the Imam to go to Iraq and accept the leadership of the populace there with the aim of beginning an uprising to overcome injustice and iniquity.

Naturally such a situation was dangerous for Yazid. The stay of Imam Husayn in Mecca continued until the season for pilgrimage when Muslims from all over the world poured in groups into Mecca in order to perform the rites of the hajj. The Imam discovered that some of the followers of Yazid had entered Mecca as pilgrims (hajjis) with the mission to kill the Imam during the rites of hajj with the arms they carried under their special pilgrimage dress (ihrami).

The Imam shortened the pilgrimage rites and decided to leave. Amidst the vast crowd of people he stood up and in a short speech announced that he was setting out for Iraq. In this short speech he also declared that he would be martyred and asked Muslims to help him in attaining the goal he had in view and to offer their lives in the path of God. On the next day he set out with his family and a group of his companions for Iraq.

Imam Husayn was determined not to give his allegiance to Yazid and knew full well that he would be killed.