He confirmed his concern about the Muslims' unity and the safety of Islam...
He confirmed his concern about the Muslims' unity and the safety of Islam, demanding an end to fights and quarrels. He wanted him to be wise enough to accept his advice and to avoid divisions that would lead the Muslim community to destruction. He informed him of his decision to fight him if he did not comply. THE FINAL JUDGMENT IS WITH ALLAH MU'AWIYAH, whose concern was only to achieve power and seize the caliphate, lent a deaf ear to Imam AL-HASAN'S letter.
MU'AWIYAH was ready to commit every crime in order to be the leader. He sent his spies and got in touch with the Imam's army leaders. He bribed some leaders and promised others with high offices if they abandoned their Imam and joined him. Many accepted the bribes and joined the enemy's camp in broad daylight. Others conspired even to lay their hand on their legitimate Imam and hand him over to MU'AWIYAH. Thus, they violated their vows of allegiance and betrayed their sublime leader.
MU'AWIYAH, the cunning fox, advised them to stay in office till the battle time, then to leave their Imam alone to face his defeat. Within few months of secret plots, MU'AWIYAH managed to have most of the tribes' chiefs on his side. Those tribes' chiefs knew that Imam AL-HASAN'S rule would be similar to his father's, hence they expected no gains from him, while MU'AWIYAH was flooding them with gifts, they preferred this world to the hereafter and sold their religion for this life's pleasures.
THE AGGRESSOR ARMY The army of MU'AWIYAH made its way towards KUFA, the then capital of Imam AL-HASAN'S (as). The Imam, in turn, encouraged his army to fight, but his efforts were in vain. Only a few were ready to obey him. The majority were in groups of different opinions. This made it difficult for him to unite them or to fight the enemy. IMAM AL-HASAN entrusted his cousin UBAYED-ALLAH IBN ABBAS, with the leadership of his army.
Everyone knew him as one of the first QURAYSHIS to swear allegiance to Imam AL-HASAN. He was very highly respected and obeyed. Moreover, he greatly hated MU'AWIYAH whose mercenaries killed both of his children. UBAYD-ALLAH'S army numbered 12,000 as IMAM AL-HASAN led another army towards Al-Medina (Iraq) and camped there. He planned to defeat the large army of MU'AWIYAH.
MU'AWIYAH was still suffering from his bitter defeat at the Battle of SIFFIN when Ali's brave men were about toe defeat MU'AWIYAH who escaped though a trick. MU'AWIYAH, therefore, decided to apply more tricks to avoid the war.