Arrival of a Christian deputation at Madinah, and their discussions without conversion on either side. The Christians designated Jesus Christ as the Son of God, and the Second Person in the Trinity. Muhammad denied this, quoting the following from the Koran: 'Jesus, the son of Mary, is only an apostle of God, and His word, which He conveyed into Mary, and a spirit proceeding from Himself. Believe, therefore, in God and His apostle, and say not three. Forbear; it will be better for you. God is only one God. Far be it from His glory that He should have a son.' Deputations from certain Arab tribes. Several lesser expeditions. Campaign of Tabuk, which ended without fighting, and the submission of many tribes, October, A.D. 630. Definite establishment of the Muslim Empire, A.D. 631. Expedition of Ali to Yaman, December, A.D. 631. Muhammad's solemn and greater pilgrimage to Mecca, i.e. 'the Al-Hijj,' or the Greater Pilgrimage, as compared with 'the Umrah,' or Lesser Pilgrimage. March, A.D. 632. His speeches at this pilgrimage, known in Muhammadan history as 'The pilgrimage of the announcement,' or 'The pilgrimage of Islam,' or 'The farewell pilgrimage.' His establishment of the lunar year, and his farewell addresses. Indisposition of Muhammad, and the three revolts--one headed by Tulaihah bin Khuwailid, a famous warrior of Najd; one by Musailamah; and one by Al-Aswad, all of which were eventually completely crushed after Muhammad's death by Abu Bakr and his generals. Another expedition to Syria projected. Muhammad's health becomes worse. His retirement to Ayesha's apartment. His final discourses. Abu Bakr appointed to lead the public prayers. Muhammad's last appearance in the mosque at Madinah. His death and burial, June, A.D. 632. From the above summary of the principal events of Muhammad's life, it will be perceived that up to the age of forty he was a student and acquirer of knowledge, much alone and occupied with his thoughts. At forty-one he began his public ministry, and stood forth as a reformer, preacher, and apostle at Mecca, and this continued till he finally left that place, in June, A.D. 622. As a reformer he proposed to do away with idols, to suppress gambling and drinking, and to abolish female infanticide, at that time much practised by the Arabs. As a preacher and apostle he urged the people to accept the belief in one God, whose injunctions were communicated to him by Gabriel for the benefit of the humanities. Prayer and ablution were also then ordained; fasting, almsgiving, and pilgrimages were instituted later on.