Over the next twenty-three years or so after the initial revelations in 610, Muhammad continued to preach the word God had spoken directly to him. At the heart of the message was the notion of “surrender” (the root meaning of the Arabic word islam, pronounced isLAAM) to the one true God. His early preaching called for social justice and equality and condemned oppression of the poor by the wealthy and powerful. Muhammad belonged to a powerful tribe called the Quraysh, who exercised considerable control over the lives of the Meccans generally. But Muhammad’s family and the clan of which they were a part were among the poorer and less influential within the tribe. Muhammad’s preaching did not endear him to the Quraysh, who made life difficult for the small community of Muslims. In 622, Muhammad and his followers made the crucial decision to move north to the city of Yathrib, whose representatives had offered the young community sanctuary. This “emigration” or Hijra marked the official beginning of the Muslim calendar. Muhammad the prophet became a statesman as well, and Yathrib became known as Madinat an-Nabi, the City of the Prophet, or Medina for short. The Muslim community grew rapidly, doing battle with the Meccans and eventually regaining access to Mecca in 630.