After his election as the Caliph, Ali deposed Muawiyah from the governorship of Syria. Muawiyah did not accept the orders of Ali and refused to vacate office. While in all other provinces, oath of allegiance was taken to Ali, under the influence of Muawiyah no one in Syria took the oath of allegiance of his authority amounted to rebellion pure and simple. At the outset of his rule, Ali planned an action against Syria to suppress the revolt.
Things however got complicated, and instead of being resolved got tangled with the lapse of time. Muawiyah enjoyed the support of the people of Syria. Ali was thus not able to take disciplinary action against Muawiyah as the Head of a State could ordinarily take against a defiant subordinate. If Muawiyah had to be deposed, military action was necessary against the people of Syria. That obviously meant the Muslims fighting against the Muslims. This was something repugnant to Islam, and as such when Ali gave the call to arms for a military action against Syria, the response from the people of Madina was very poor. Expedition against Syria had therefore to be deferred for some reason or the other. The delay worked to the advantage of Muawiyah, as thereby he consolidated his power.
Difficulties were created for Ali, when Talha and Zubair who had taken the oath of allegiance to him defected and were joined by Ayesha. Ayesha, Talha and Zubair occupied Basra and Ali had to lead a force against Basra instead of against Syria. Ali won the victory over the confederates but this was achieved at a heavy cost. Over ten thousand persons died in this battle and their death was deeply mourned by the Muslim world. That also proved to be a drain at the limited resources at the disposal of Ali. When after the Basra campaign Ali turned to Syria, Muawiyah had become stronger, and things for Ali became all the more difficult.