They knew that the greed for power and glory of these two...
They knew that the greed for power and glory of these two men was slowly destroying the true Islam. Hazrat Muslim reported back to Imam Husayn that most of the people in Kufa wanted him as their Imam to guide them and also advised him to come to Kufa. Yazid had spies in Kufa. He heard from them, about invitation to Imam Husayn and the arrival of Hazrat Muslim in Kufa. Being an evil man, Yazid was full of anger, and he replaced the Governor of Kufa with one of his own men - Ibn Ziyad.
Ibn Ziyad was told to arrest Muslim and kill him and do all that was necessary to suppress the Shi'as in Kufa. Ibn Ziyad was a cruel and unjust man. As soon as he arrived in Kufa, he threatened the people of Kufa with death punishment if they were found to engage in any activity against Yazid. He ordered them to surrender Hazrat Muslim to him. On 8th Dhul-Hajj, soldiers of Ibn Ziyad arrested Hazrat Muslim. He was chained and dragged to the Court of Ibn Ziyad.
He then ordered Hazrat Muslim to be taken to the roof of the palace to be killed, and his body thrown to the ground. Hazrat Muslim was dragged up the steps. He was killed and his body was thrown to the ground. Hazrat Muslim's head was cut off and hung on the City gate to remind and scare the people of Kufa. Hazrat Muslim's two sons, Muhammad and Ibrahim, were also arrested and killed mercilessly.
In the meantime, Imam Husayn and his companions in Mecca were preparing to perform the duty of Hajj when his friends in Mecca informed him that Yazid's men were planning to have him and his followers murdered during the Hajj. Imam Husayn did not wish the House of Allah to be turned into a battlefield. Therefore, he decided to leave Mecca without performing Hajj. On 8th Dhul-Hajj, the very day on which Hazrat Muslim was murdered in Kufa, Imam Husayn's caravan left Mecca.
Imam Husayn did not know of Hazrat Muslim's death. The journey was made on camels and horses. The weather was extremely hot at that time of year. The Imam, his children, ladies and friends suffered great hardship during the journey. During the journey, Imam learned of the death of Hazrat Muslim and the cruel way in which he had been killed.
When Yazid came to know that Imam Husayn was heading towards Kufa, he immediately sent Hurr, at the time one of his army commanders to stop the Imam from joining his followers in Kufa. Hurr, with 1,000 horsemen, met Imam Husayn and his companions at a place a few miles outside Kufa.