Imam Husayn left al-Madina al-Munawwara. He went to Makkah to perform the Haj. Yazeed bin Mu'awiyah knew about al-Husayn's travel. He sent some spies to kill him.
So, Imam Husayn decided to leave Makkah. He said:
I don't want them to violate the Holiness of the Ka'aba.
Imam Husayn headed for Kufa. On the way, he heard that Ubaidullah bin Ziyad's guards killed Muslim bin Aqeel, Hani, Qais bin Mudhir al-Saidawy and others.
A thousand horsemen surprised Imam Husayn's caravan. They prevented it from advancing towards Karbala. Then the military battalions came successively. Their number was four thousand fighters. Seventy persons came with Imam Husayn. They were his family and his supporters.
When Ubaidullah bin Ziyad's army asked Imam Husayn to surrender and to pay homage to Yazeed bin Mu'awiyah, he said his famous words:
Abasement is far away from us!
Imam Husayn was ready to die a martyr for Islam.
On the morning of Muharram 10th, the Battle of Karbala took place. Thousands of fighters launched a savage attack against Imam Husayn and his companions. They faced the attack bravely. Strong fights took place. They astonished the enemies. Only seventy fighters were fighting from the early hours of the morning till afternoon.
All of Imam Husayn's companions passed away. Imam Husayn was alone. Still he attacked Ubaidullah bin Ziyad's Army. He was fighting bravely.
Ubaidullah bin Ziyad's Army killed Imam Husayn. It beheaded the martyrs, tied their heads to the spears and burnt the tents. Then it took the women and children prisoners.