In June 622, warned of a plot to assassinate him, Muhammad secretly slipped out of Mecca with Abu Bakr and moved his followers to the nearby town of Yathrib (later to be known as Medina) in a large agricultural oasis, where the people there accepted Islam. Those who migrated from Mecca along with Muhammad became known as muhajirun. This marks the "Hegira" or "emigration," and the beginning of the Islamic calendar.