Treaty of Imam Hasan (a) with Mu'awiya

Why the Imam made peace

After Imam Ali's (a) martyrdom the people of Kufa pledged allegiance to Imam Hasan (a), but Mu'awiya refused to recognise him and marched from Syria. The Imam's army was riddled with tribal chiefs who secretly wrote to Mu'awiya offering to hand the Imam over; his vanguard commander deserted for money; and a Kharijite wounded him at Sabat. With his forces disintegrating and his followers exposed to slaughter, the Imam accepted a treaty rather than lead the Shia into a war they could not win.

The terms

Mu'awiya took the caliphate on written conditions: he would govern by the Qur'an and the Prophet's (s) practice, would not appoint a successor, would not persecute the Shia or pursue Imam Ali's (a) partisans, and would guarantee the safety of the Imam's household. The treaty is commonly dated to Rabi al-Awwal 41 AH, remembered by Muslims as the "year of the community" because it ended the civil war.

Aftermath

Mu'awiya broke every clause, cursing Ali (a) from the pulpits, killing Hujr b. Adi and his companions, and finally making his son Yazid heir — the act that led Imam Husayn (a) to refuse allegiance two decades later. Some companions reproached Imam Hasan (a) for the peace; the Imams after him defended it as the only way to preserve the Shia and expose the Umayyads by their own conduct.