The first example that we find of the power exercised by women is without doubt the Queen of Sheba; while a second example follows within a few years after the failure of the expedition of Ælius Gallus, in the person of Queen Balkis, whose real name was Belkama or Yalkama, and who was sufficiently strong-minded to amalgamate two kingdoms by marrying her rival, whom she immediately removed by poison. About A.D. 120 the great dam of Saba or Mareb burst, spreading wholesale destruction throughout the wide fertile valley below it. About this period, too, an expedition was carried by the then King Tubba el-Akran as far as Samarcand, and thence into China; and in A.D. 206, Abou Kariba, one of the most illustrious of all the Himyaric kings, invaded Chaldæa and defeated the Tartars of Adirbijan. He started on a second expedition to conquer Syria, but returned after taking the Hejaz to the Yemen, where he is said to have renounced idolatry and embraced Judaism. A legend, quoted by Sir Lambert Playfair in his ‘History of the Yemen,’ tells of the introduction of the Jewish faith into the Yemen during the reign of this Sultan. It savours of the priests of Baal; for, wishing to put to the test the merits of Judaism and idolatry, the priests of either creed proceeded to a certain spot whence fire emerged from the ground. Pushed on by the crowd, the test was tried, and while the Jewish priests passed through the flame unscathed, the idolaters perished. But the feeling between the two was by no means destined from this fact to become a cordial one, and constant fights occurred between the two parties. Although Christianity seems to have appeared in the Yemen previous to the year 297 A.D., it was not until that date that it became a religion of importance in the country. It was during the reign of the king Tubba ibn Hassan, who held the throne at this period, that Christianity was introduced into Abyssinia; and about the middle half of the fourth century the Emperor Constantius sent a certain bishop, Theophilus Indus, to convert the Yemenis, of whom the king was so far tolerant, even if he did not himself embrace Christianity, to allow the building of churches. One was erected at Zafar, near Yerim; another at Aden; and a third at a port in the Arabian Sea, supposed generally to be Hormuzd.