Magadaxo was founded about the middle of the tenth century and remained the most powerful city on this coast for more than seventy years, when the arrival of another expedition from the Persian Gulf led to the establishment of a rival settlement further south. The leader of this expedition was named ʻAlī, one of the seven sons of a certain Sultan Ḥasan of Shiraz: because his mother was an Abyssinian, he was looked down upon with contempt by his brothers, whose cruel treatment of him after the death of their father, determined him to leave his native land and seek a home elsewhere. Accordingly, with his wife and children and a small body of followers, he set sail from the island of Ormuz, and avoiding Magadaxo, whose inhabitants belonged to a different sect, and having heard that gold was to be found on the Zanzibar coast, he pushed on to the south and founded the city of Kiloa, where he could maintain a position of independence and be free from the interference of his predecessors further north. [1115] In this way a number of Arab towns sprang up along the east coast from the Gulf of Aden to the Tropic of Capricorn, on the fringe of what was called by the mediæval Arab geographers the country of the Zanj. Whatever efforts may have been made by the Muhammadan settlers to convert the Zanj, no record of them seems to have survived. There is a curious story preserved in an old collection of travels written probably in the early part of the tenth century, which represents Islam as having been introduced among one of these tribes by the king of it himself. An Arab trading vessel was driven out of its course by a tempest in the year A.D. 922 and carried to the country of the man-eating Zanj, where the crew expected certain death. On the contrary, the king of the place received them kindly and entertained them hospitably for several months, while they disposed of their merchandise on advantageous terms; but the merchants repaid his kindness with foul treachery, by seizing him and his attendants when they came on board to bid them farewell, and then carrying them off as slaves to Omam. Some years later the same merchants were driven by a storm to the same port, where they were recognised by the natives who surrounded them in their canoes; giving themselves up for lost this time, they repeated for one another the prayers for the dead. They were taken before the king, whom they discovered to their surprise and confusion to be the same they had so shamefully treated some years before. Instead, however, of taking vengeance upon them for their treacherous conduct, he spared their lives and allowed them to sell their goods, but rejected with scorn the rich presents they offered. Before they left, one of the party ventured to ask the king to tell the story of his escape. He described how he had been taken as a slave to Baṣrah and thence to Baghdād, where he was converted to Islam and instructed in the faith; escaping from his master, he joined a caravan