The birthplace in AD 570 of the prophet Muhammad, it was the scene of his early teachings before his emigration to Medina in 622 (the Hegira). On Muhammad's return to Mecca in 630 it became the centre of the new Muslim faith. It is the site of the Great Mosque and the Kaaba, and is a centre of Islamic ritual, including the haj pilgrimage which leads thousands of visitors to the city each year.