The city of Yathrib had been long occupied by Jews whom some national disaster, possibly the persecution under Hadrian, had driven from their own country, when a party of wandering emigrants, the two Arab clans of Khazraj and Aws, arrived at Yathrib and were admitted to a share in the territory. As their numbers increased they encroached more and more on the power of the Jewish rulers, and finally, towards the end of the fifth century, the government of the city passed entirely into their hands. Some of the Arabs had embraced the Jewish religion, and many of the former masters of the city still dwelt there in the service of their conquerors, so that it contained in Muḥammad’s time a considerable Jewish population. The people of Yathrib were thus familiar with the idea of a Messiah who was to come, and were consequently more capable of understanding the claim of Muḥammad to be accepted as the Prophet of God, than were the idolatrous Meccans to whom such an idea was entirely foreign and especially distasteful to the Quraysh, whose supremacy over the other tribes and whose worldly prosperity arose from the fact that they were the hereditary guardians of the national collection of idols kept in the sacred enclosure of the Kaʻbah. Further, the city of Yathrib was distracted by incessant civil discord through a long-standing feud between the Banū Khazraj and the Banū Aws. The citizens lived in uncertainty and suspense, and anything likely to bind the conflicting parties together by a tie of common interest could not but prove a boon to the city. Just as the mediæval republics of Northern Italy chose a stranger to hold the chief post in their cities in order to maintain some balance of power between the rival factions, and prevent, if possible, the civil strife which was so ruinous to commerce and the general welfare, so the Yathribites would not look upon the arrival of a stranger with suspicion, even though he was likely to usurp or gain permission to assume the vacant authority. On the contrary, one of the reasons for the warm welcome which Muḥammad received in Medina would seem to be that the adoption of Islam appeared to the more thoughtful of its citizens to be a remedy for the disorders from which their society was suffering, by its orderly discipline of life and its bringing the unruly passions of men under the discipline of laws enunciated by an authority superior to individual caprice. [22] These facts go far to explain how eight years after the Hijrah Muḥammad could, at the head of 10,000 followers, enter the city in which he had laboured for ten years with so meagre a result.