Mohammed - the Prophet on his birth day

The Prophet Mohammed was born in the Arabian city of Mecca, roughly 570 years after the birth of another famous prophet, Jesus. Abdullah, his father, had died several weeks before his birth, followed by the death of his mother Aminah around the age of six. The grandfather who had stepped in as Mohammed's father died shortly after.
He was taken in by his uncle Abu-Talib, whom the young Mohammed began to assist as a shepherd, caravanner and shopkeeper. At the age of 25, Mohammed married Khadijah, a rich widow, his senior and his employer. Together they had six children but his two sons died young. His profession as trader brought him into contact with many different groups - Jews, Christians, Chinese, Hindus and so on. He also became active in a charitable brotherhood organised by another uncle.
In AD 605, the Kaaba at Mecca was assaulted first by fire, then by torrential rain. Mohammed participated in its rebuilding, setting in place a black stone in one of its walls and prompting the tradition of circumambulation
1 that occurs every year during the hadj, or pilgrimage. After this episode, he spent a good deal of time in spiritual study.

A Visitation from the Angel Gabriel

For the next few years, he fasted, prayed and meditated during the month of Ramadan in a mountain cave
2. Towards the end of one such retreat, Mohammed received a vision from the angel Gabriel, who told him he had been chosen to be God's messenger to mankind. After being instructed by the angel on the finer points of the message, Mohammed returned home deeply disturbed.
He was even more worried when he received no more visions for three years, during which time Mohammed devoted more and more time to prayer and meditation. When the visions returned, God told Mohammed to preach against evil, idolatry and to promote the virtues of monotheism and charity to the needy. As his ministry in Mecca grew, he inevitably fell foul of the city's elders. Mohammed experienced the mi'raj, a vision in which he is received into Heaven and is witness to its wonders. He is given the Islamic ritual prayer, the salaat, to take to the people. Unfortunately, the people of Mecca and the city of Ta'if drove the Prophet off in a hail of stones.
The City of Medina
In 622, of the Christian era, to escape persecution, Mohammed took his supporters and headed for Medina
3. Mohammed and his followers travelled extensively, taking his message to various tribes with varying degrees of success. In Medina, Mohammed became both a spiritual and temporal leader, organising the wealthier of the local families and helping to establish Medina as a city-state, with a written constitution.
The following decade was marked by a series of small conflicts with rival cities and tribes, as well as expansion of support for Mohammed and the new religion. In 630, Mecca surrendered to Mohammed in the face of such odds. In spite of all the transgressions the Meccans had made against Mohammed and his followers, he chose to take no reprisal against them.
Final Pilgrimage
Mohammed made one final pilgrimage to Mecca in 632. There he gave a sermon to a large number of Muslims, a synopsis of Islam
4, the new faith. He spoke of belief in one God without images and symbols, the equality of believers, the importance of piety and selflessness, better treatment of women and equal distribution of wealth and inheritance.
Upon his return to Medina, Mohammed fell ill with a fever, dying several weeks later. At the time of his death, the Prophet left a new state with a new system of law and ethics balanced between the spiritual and temporal, and the peoples of Arabia, Iraq and Palestine united under a common religion. Within a century, Islam and Mohammed's message spread far beyond the desert sands, from Spain to China.
1 Literally, walking around in a circle. In this case, around the Kaaba shrine.
2 The cave is called Ghar-i-Hira - the cave of research.
3 This event is called the Hegira or the flight, and the Moslem calendar is dated from this point.
4 Islam means 'submission to the will of God'. A Muslim is 'one who submits to the will of God'.

source BBC