Battle of Siffin
The reign of Caliph Ali was full of turbulence. Though Abdallah ibn Amir, did not take part in the Battle of Siffin, fought between the forces of Caliph Ali and Muawiyah, he supported the vengeance of Caliph Uthman's murder. After the murder of Caliph Ali in 661, his eldest son Hassan ibn Ali became the caliph. He was pressured by the Syrian governor Muawiyah to resign as caliph. Avoiding another civil war, Hassan ibn Ali resigned in the favor of Muawiyah six months later. During this Abdallah ibn Amir supported the caliphate of Muawiyah.