TOWARDS the end of the sixth year of the hijrah, the Prophet decided to perform, accompanied by his followers, the "lesser pilgrimage" or "pious visit" ('umrah) to Mecca. Although for nearly six years there had been a more or less permanent state of war between the Muslim community at Medina and the pagan oligarchy of Mecca, the Prophet did not anticipate any hostilities on that occasion, since the month of Dhu'l-Qa'dah, in which he intended to reach Mecca, was one of the four "sacred months" during which, in accordance with time-honoured Arabian custom, all warfare was outlawed, and particularly so in and around the Holy City. A call was issued to some of the allied bedouin tribes in the vicinity of Medina to join the Prophet on this pilgrimage, but most of them excused themselves on some pretext or other (see note 10 on verse 11 of this surah). Thus, the Prophet's party which set out for Mecca consisted of only 1400-1500 men, all of them dressed in the pilgrim's garb (ihram) and, apart from their sheathed swords, unarmed. On learning of the Prophet's approach, the Meccans decided - against all Arabian tradition - to oppose the entry of the pilgrims by force of arms. A detachment of two hundred horsemen under the command of Khalid ibn al-Walid (who was destined to embrace Islam less than two years later) was sent out to intercept the Prophet's party, while several thousand heavily-armed men took up positions around Mecca. Since the Prophet was neither inclined nor in a position to give battle, he turned westwards from Bir 'Usfan (a place about one day's journey from Mecca) and alighted on the plain of Al-Hudaybiyyah, where he and his followers remained for the next few days. There and then negotiations were opened between the Muslims and the Meccan oligarchy. After some preliminary discussions conducted by various emissaries of both parties, the Prophet sent 'Uthman ibn 'Affan (who belonged to one of the most influential Meccan clans) as his envoy. Shortly after 'Uthmin's arrival in Mecca, a rumour that he had been murdered reached the Muslim camp at Hudaybiyyah. Thereupon the Prophet, expecting a treacherous attack by the Meccans, assembled his followers and, sitting under a wild acacia tree, took, amid scenes of the greatest enthusiasm, a pledge from each one of his followers that they would remain steadfast and fight unto death; and after the revelation of verse 18 of this surah, this "Pledge of the Tree" became known to history as Bay'at ar-Ridwan ("the Pledge of [God's] Goodly Acceptance"). When a few days later the rumour of 'Uthmin's death proved false and he himself returned to Hudaybiyyah, it became clear that the Meccans were prepared to conclude a truce. A treaty was drawn up, stipulating, among other provisions, that all warfare between Mecca and Medina should be suspended for ten years, and that the Prophet and his followers should refrain from entering Mecca that year, but would be free to do so the following year. The Prophet also agreed that if a Meccan minor or any other person under guardianship should go over to the Muslims without the permission of his guardian, he would be returned to the latter; but should any follower of the Prophet - whether minor or of age - go over to the Quraysh of his own free will, he or she would not be returned. Although this last stipulation appeared at first glance to be disadvantageous to the Muslims, it is obvious that the Prophet agreed to it in pursuance of the principle that "there shall be no coercion in matters of faith" (2:256). The Truce of Hudaybiyyah was to prove of the greatest importance to the future of Islam. For the first time in six years peaceful contacts were established between Mecca and Medina, and thus the way was opened to the penetration of Islamic ideas into the citadel of Arabian paganism. The Meccans who had occasion to visit the Muslim camp at Hudaybiyyah returned deeply impressed by the spirit and the unity of Muhammad's followers, and many of them began to waver in their hostility towards the faith preached by him. As soon as the perennial warfare came to an end and people of both sides could meet freely, new converts rallied around the Prophet, first in tens, then in hundreds, then in thousands - so much so that when the pagan Quraysh broke the truce two years after its Conclusion, the Prophet could and did occupy Mecca almost without resistance. Thus, in fact if not in appearance, the Truce of Hudaybiyyah ushered in the moral and political victory of Islam over all Arabia. In the consensus of all the authorities, the surah commemorating this victory was revealed during the Prophet's return march from Hudaybiyyah to Medina.