Once a resident of Mecca, Prophet Muhammad was forced to flee in 622 after being persecuted and threatened with assassination. In 628, the Prophet Muhammad set out with about 1400 Muslims from Medina to perform umrah, the minor pilgrimage. When they reached the outskirts of Mecca, the Prophet sent an emissary to the Meccans for peace agreement. The Muslims were not permitted to perform the pilgrimage that year, but an agreement was reached between the Muslims and Quraysh called ‘Treaty of Hudaybiyah’. According to the treaty, when the Muslims returned for the pilgrimage, the Meccans would clear the city so that the Muslims could perform the ritual peacefully. Finally, the treaty outlined a plan for 10 years of peace between the two sides, preventing any bloodshed. However, two years later there was a violation of the agreement. One of the tribes allied with the Meccans attacked and killed some members of a tribe allied with the Muslims. This incident dissolved the treaty.

By this time, the Muslims had become a formidable force and so in 630 the Prophet Muhammad decided to take an army of 10,000 towards Mecca. Once the Muslims had reached Mecca, the leaders of Quraysh surrendered.  The Meccans were afraid about the impending conquest of their. When the Prophet Muhammad and the Muslims entered the area of the Kaba, he announced clemency for everyone in Mecca who no longer wished to fight the Muslims: “This day no reproach shall be on you. God will forgive you; He is the Most Merciful of the Merciful. You can go away!”

Many of the Meccans, who were expecting some sort of punishment, were surprised by the Prophet’s statement and some decided to become Muslim. Thus, the conquest of Mecca was bloodless and ended years of warfare and violence between Quraysh and the Muslims. Prophet Muhammad could have exacted revenge, in accordance with the traditions of the Arabs, but instead he showed mercy on the Meccans. This is an important reminder for Muslims even to the present day about how conflict should be addressed. Finally, the conquest was a defining moment because it established Islam on the Arabian Peninsula, from there it spread to become a major world religion.

Reference:

http://www.mapsofworld.com/on-this-day/january-11-630-the-prophet-muhammad-conquers-mecca

http://insideislam.wisc.edu/2012/04/important-events-the-conquest-of-mecca/