The conquest of Makkah began after the Treaty of Hudaybiyyah was broken by an ally of Quraiysh by attacking and killing some men of an ally of Muslims, the Khuzas. The Khuzas sought help from Prophet Muhammad (SAWW). After that, an army of 10,000 Muslims led by Prophet Muhammad (SAWW) set out for Makkah from Madina on 10th Ramadan, 8 AH.
The army was directed to march very cautiously so that the tribes of Quraiysh are caught unawares when they reach there.
When the Muslims were about to enter Makkah, the only chieftain of the city, Abu Sufiyan (RA), came to meet the Prophet (SAWW) and accepted Islam, while the residents of the city did not resist upon conquering of the land.
Then the Muslim army made an announcement that whoever will enter the house of Abu Sufiyan (RA) will be protected, whoever will shut the door of his house will be protected and whoever will enter Masjid al Haram will be protected.
Emirs of troops were directed not to fight anybody except the ones who come to fight them. “This is the day of mercy.”
After the conquest of Makkah, Prophet Muhammed (SAWW) headed towards Khana e Ka’aba and performed Tawaaf there. Then he smashed all the idols placed inside or outside of Ka’aba, while reciting, “The truth has come and falsehood has vanished. Surely, falsehood is bound to vanish!” (17:81).
On this occasion, the Prophet (SAWW) also addressed the people: “There is no God but Allah alone. He has no associate. He has made good His promise and helped his servant. He has put to flight the confederates. Every claim of privilege or blood or property is abolished by me except the custody of the temple and the watering of the pilgrims … O Qureish, God has taken from you the haughtiness of the days of paganism and its veneration of ancestors. Man springs from Adam and Adam springs from dust.”
He also recited from Quran, “We have created you from male and female and made you into nations and tribes so that you may know one another. The most noble of you, in the sight of God, is the most pious” (49:13).