The campaign carried on from Merv, the see of the Chaldean Bishop of Tartary, succeeded to such a degree as to win to Christianity a large number of the female members of the ruling families, and an important nomad tribe called the Keraite, whose capital was in Qarakorum, in the Altai Mountains. Yet, of the actual invaders of the West none were won over, being frankly pagans, making a policy of equal freedom for all religions, but adhering to none. Thus, while several were of Christian mothers, and were even baptized in infancy, receiving Christian names, they retained no sign of their origin when come to power, changing the names of their infancy to Tartar titles, and forgetting the religion of their childhood. In China the missionaries had had equal success, as is witnessed by the tablet found at Se-gan-fu, which described the favour which had met their doctrine from both king and country, mentioning also the names of Chinese Christian bishops and mandarins of that faith. From this interesting tablet it was first ascertained that, up to A.D. 781, the date of the inscription, the Chaldeans had pushed so far as China, and the revelation of the existence of a recognised Church there was so astonishing to the critics, as to throw discredit upon the monument for some time.[43] [Sidenote: THE CHALDEANS IN MONGOLIA] Towards the fall of the Khalifate, the Chaldeans, seeing their Church in Persia almost extinct, and in Mesopotamia confined, and melting before the gradual absorption by Islam, turned the eyes of hope towards these Mongol states, aspiring to find in them a weapon to drive out Islam. That it acted against Islam, dealing it almost a death-blow, is well known; but the too sanguine Christians did not foresee that it would be at the hands of two of the Mongol Khans, one a baptized Christian, that the Nestorian Church should suffer persecution and massacre, and its remnants be forced to save themselves by flight to the inaccessible mountains of the Kurds. For it was not at all a zeal for Christianity that urged the Mongols on, though the reports by Chaldean priests of Western wealth may have excited the greed of the Khans. Just at the period before the great invasions, the opening of the 13th century, missionary effort had redoubled, and Roman Catholics for the first time appeared on the scene, many courageous monks daring the dangerous voyage from Europe to the unknown East. The tolerance of Chengiz Khan, first Mongol emperor, was responsible in a great measure for this renewed enthusiasm, which was the more sanguine in remembering that Islam does not proselytise. But the terrible invasion of Hulagu Khan, that swept great and small, faithful and infidel, before it, broke both Christianity and Islam for a time, striking at the heart of both, Bagdad, which was reduced to ruins among scenes of the most terrible inhumanity ever witnessed.[44]