h change. Muhammad and his small band of followers migrated to the town of Yathrib in the north. Yathrib later became known as Medina ("city of the Prophet"). Monotheism quickly spread, as the people were open to the new faith. The Hijrah (migration) of 622 marks the beginning of the Muslim calendar. Muhammad was the ruler of Medina, which later became the seat of the caliphate. The rapid growth of Is
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