The Conquer of Mecca meant the fall of this city (in actual Saudi Arabia) to the hands of Muslims lead by Prophet Muhammad in January 630 AD (8 AH).
In 628, the Meccan tribe of the Quraysh and the Islamic community of Medina had signed a truce for 10 years, the Treaty of Hudaybiyyah. According to the terms of the Treaty, the Arabic tribes were offered to join whatever side they chose, either the Muslims or the Quraysh. If any of the tribes was attacked, its allies had the right to retaliate. As a consequence, the Banu Bakr aligned with the Quraysh and the Khuza´ah joined Prophet Muhammad.
Peace reigned for some time, but motives with origins that date back to pre-islamic era, triggered hostilities that lead to the Banu Bakr attacking the Banu Khuza´ah disregarding the dispositions of the treaty. The Quraysh aided the Banu Bakr with men and arms, and raided Al-wateer in Sha´ban during the night.
Pressed by the attacks of their enemies, the members of the Khuza´ah tribe sought refuge in the Sanctuary of Kaaba, where according to the traditions, no blood should be shed. Nevertheless, their lives were not spared, and Nawfal, chief of the Banu Bakr, chased them and massacred his adversaries. The Khuza´ah managed to send a delegation to inform Muhammad of the violation of the agreement and seek for the help of the Muslims from Medina, being their allies.
Soon after the massacre of Al-wateer, the Quraysh sent a delegation to Muhammad, pleading to maintain the treaty´s conditions and offering material compensation. By that time, Muslims had already taken a decision and were gathering strength for a final and definitive attack to Mecca.
Muhammad started to raise a great army. The final objective (Mecca) was kept a secret, and not even Muhammad´s closest friends and generals didn’t know the plan.
On December 29 629, the Muslim army headed Mecca. Volunteers and contingents from allied tribes joined Muhammad on his way, increasing the army´s sized up to 10.000 men, becoming the biggest army in Muslim history. The army stayed at Marr-uz-Zahran, 10 km north of Mecca, and Muhammad ordered every man to light a fire, so that their adversaries would overestimate the size of the army.
Mecca is situated in the Valley of Ibrahim, surrounded by rugged black terrain, 300 metres steep at some points. There were only 4 entries through passes between the hills. Muhammad divided his army into 4, one to advance through each pass. The main column, in which Muhammad himself was, was commanded by Abu Ubaidah Ibn al Jarrah. Its mission was to enter Mecca through the main Medina route, from the northwest.
Their tactic was to advance simultaneously from all four sides, with only one main objective. This would disperse the enemy and avoid its concentration in one point. This way, even if one or two attacking columns found strong resistance and was incapable of breaking it, the attack would be able to continue from the other flanks. This would also block the Quraysh from escaping.
Muhammad emphasized his order to avoid fight unless Quraysh attacked. The Muslim army entered Mecca on Monday 11 January 630. The entry was peaceful and with no bloodshed in three of the sectors, with the only exception of the column commanded by Khalid ibn al-Walid. Embittered anti-muslims gathered a group of Quraysh fighters and attacked the Muslims with swords and bows. After a short skirmish, Qurays ended surrendering, after losing 12 men, while Muslim losses where only two warriors.
God has made Mecca a sanctuary since the day He created the Heavens and the Earth, and it will remain a sanctuary by virtue of the sanctity God has bestowed on it until the Day of Resurrection. It (fighting in it) was not made lawful to anyone before me. Nor will it be made lawful to anyone after me, and it was not made lawful for me except for a short period of time. Its animals (that can be hunted) should not be chased, nor should its trees be cut, nor its vegetation or grass uprooted, nor its Luqata (most things) picked up except by one who makes a public announcement about it.