After the battle of Jamal was over, Imam Ali (A) returned from Basra to Kufa in Rajab of 36 A.H. He decided to set up the capital of his government in Kufa because it was more centrally placed in the Muslim Empire, and he could halt Muawiya's progress into Iraq.
Before marching towards Muawiya, Imam Ali (A) tried to settle matters peacefully by sending Jarir, the governor of Hamdan, to Syria as an envoy. However, Jarir became so engrossed in the entertainment that Muawiya put his way, that he wasted his time in Syria. He finally returned three months later with the useless message that peace could only be negotiated if the murderers of Uthman were brought to justice.
Imam Ali (A) decided that matters could be only decided by war, so he marched without delay through the Mesopotamian desert to Riqqa at the banks of the Euphrates. After crossing the river by constructing a bridge they came across the Syrian outposts at Sur al-Rum. There were a few skirmishes between the armies but the Syrians gave way and in the month of Zilhaj of 36 A.H., the army of Imam Ali (A) came into sight of Muawiya's main forces, which had already camped at Siffin.
At Siffin, Muawiya had stationed his general, Abul Awr, with 10,000 men on the river to stop the access to water for Imam Ali's (A) army. Imam Ali (A) sent a message to Muawiya that this action was not necessary because, after all, the people whom he was refusing water were also Muslims. He further assured Muawiya that if the situation had been reversed, the river would have been open to both armies. However, Muawiya sent back a message that the murderers of Uthman had not allowed him any water when they had laid siege to his palace, and Muawiya was avenging that action.
Imam Ali (A) knew that this situation would be intolerable and he launched an attack under Malike Ashtar. The brave commander secured the river after heavy fighting and Abul Awr was dislodged from its banks. Having control of the river, Imam Ali (A) kept to his word and allowed unlimited access to Muawiya's side.
Imam Ali (A) divided his army of 90,000 men into seven units each commanded by brave warriors. Muawiya similarly divided his army of 120,000 men into seven columns. Everyday one column from each army would engage one another in combat.
The battles were mostly restricted to single combats or small groups fighting because Imam Ali (A) was trying to avoid the serious loss of Muslim lives that would have resulted from a full scale battle. The month of Zilhaj ended in this manner and the month of Muharram, in which fighting is forbidden, set in. During this month, Imam Ali (A) tried hard to resolve the crisis by negotiation, but to no avail. He pointed out that he was ready to punish the murderers of Uthman if Muawiya would point them out. However, Muawiya did not wish the matter to end so easily, because it was the issue of Uthman's unavenged death that had enabled him to gather such a large army.
In the month of Safar fighting was resumed. For a week, fierce battles raged all day. Everyday the conflict got more severe and bitter. In the second week Imam Ali (A) came to the battlefield for the first time. After a series of single combats, in which he overcame every opponent with his awesome skill, no body would come to fight him.
He was forced to disguise himself to get anybody to challenge him. On one such occasion, an unsuspecting warrior from Muawiya's side attacked Imam Ali (A). The man was struck with a single sweep of Zulfiqar with such force by Imam Ali (A) that the upper half of his body was severed from the lower half. Those who watched thought that the blow had missed, and it was only when the horse moved and the two halves fell to the ground, that people realised what had happened.
Day after day the loss of lives increased, especially in the ranks of Muawiya. However, Imam Ali (A) also lost several distinguished Companions of the Holy Prophet (S) from his side. Amongst them were Hashim bin Utba and Ammar Yasir.
Ammar, who was 93 years old, had been informed by the Holy Prophet (S) that he would die fighting rebels and enemies of Islam. This was well known by all, and when he died there was some commotion in Muawiya's army. He managed to quieten them down by saying that, since Ammar had been brought to fight by Imam Ali (A), it was he who was the cause of his death. He said that Imam Ali (A) therefore was the rebel that the prophecy talked about, and not Muawiya. This incredible argument was accepted by his men and war continued until the 13th night.
On that day the commander-in-chief of Imam Ali's (A) army, Malike Ashtar, attacked the enemy ferociously. His shout of Allahu Akbar, every time he killed a man, was heard no less than 400 times.
The hero of the battle began to bring on victory when Amr al-Aas on Muawiya's side said, "Call the enemy to the Word of God."
Muawiya eagerly accepted these words and his men raised 500 copies of the Holy Qur'an on their spears, saying that the Holy Book would decide their differences. This trick had a strange effect on some people in the army of Imam Ali (A), who dropped their weapons and agreed that the Holy Qur'an should decide the matter.
Imam Ali (A) stepped into the battlefield urging his men to continue fighting and ignore the tricks of Muawiya, but they disobeyed. The war thus came to an unsatisfactory end, and it was decided that one representative from each side should meet to reach a final decision.
Imam Ali (A) wanted Abdullah bin Abbas or Malike Ashtar to represent him, but his men insisted that Abu Musa Ash'ari be chosen instead. Muawiya appointed Amr al-Aas to represent him. Abu Musa had neither wit nor tact and was no match for the cunning Amr al-Aas.
In the meeting that took place some months later, Abu Musa was badly tricked by Amr into giving up the rights of Imam Ali (A).
Muawiya thus managed to escape certain defeat at Siffin. The damage done at the battle was great. Muawiya lost 45,000 men and 25,000 men were killed on the side of Imam Ali (A).
(Courtesy of:- Shia Ithna asheri Madressa)