Why did Imam Husayn (a.s.) leave Madina for Karbala?
The Imam didn’t go directly from Madina to Karbala. He first went to Mecca, and this was before Hajj (pilgrimage) time.
He started to talk to people about the political scene, about Yazid and his conduct. How he’s openly violating God’s laws, and how oppressive he is. He spoke to the people about their responsibility of standing against injustices. He provoked them to stand against Yazid, and he continued these activities until Hajj season arrived.
During the Hajj season, which starts in Shawwal, more people came from around the Islamic world. The Imam took advantage of this time to try and gather more support against Yazid. While he was doing this, the people in Kufa got the news of what the Imam was doing.
Being fed up with the central government based in Damascus (and some of course because of their Islamic responsibility), the Kufans sent letters to the Imam requesting him to come to Kufa, pledging that they will help him against Yazid.
The Imam sent a representative to test the waters. He was supposed to see how loyal the people were going to be. He was supposed to see if there was any truth to the letters. After some time, Muslim bin Aqil (the Imam’s representative to Kufa) wrote a letter telling the Imam that the people were ready for him to come to Kufa.
On the ninth of Zhil Hijja, the Imam realised the government may assassinate him, so he left towards Kufa, since that was the only place he had support. On the way, he got news that things were changing in Kufa, but there was still hope of him being able to change things if he could reach the city.
When he got closer to Kufa , forces loyal to Yazid sent an army of 1000 soldiers to prevent the Imam from going towards Kufa, and from returning to Madina. The Imam chose another direction and started moving in that direction. The order came to stop the Imam in a bare land, and so when the Imam arrived in Karbala, he was stopped and prevented from leaving.
They presented the Imam with two options: one was to surrender and pledge allegiance to Yazid, and the other was to get killed. The Imam decided not to pledge allegiance even if that meant he will have to fight until death.
So the Imam’s objective was to stand against Yazid. If he had the support in Kufa, he would have gone on to fight Yazid as his father and brother fought Muawiya.
When the people of Kufa said they were ready to support the Imam, the Imam practically showed his readiness to lead the people against oppression. When the people retracted their support, he continued the mission of standing up against injustice and refusing to pledge allegiance to a tyrant. He was willing to get killed to awaken the people and make them realise the reality of Yazid’s illegitimate rule.
Answered by: Sheikh Hamza Sodagar