The more purely missionary efforts which were being made contemporaneously with the events just related, were directed chiefly to China which, on the death of Mangu, had fallen to the lot of Kublai Khan. The opportunity for these was opened out by the relations already established with the Mongolians on other grounds. The first missionaries found Nestorian Christians who were subjects and others who were captives acting as clerks, artisans and merchants at the Tartar Court. Besides these, others in search of fortune or adventure occasionally found their way from the West. Such were two Venetians, Nicolo and Maffeo Polo, who, having traded with the Tartars of the Golden Horde (1260), were led by force of circumstances further into Asia, until they reached China. Kublai sent them back to Europe with a request to the Pope for at least a hundred well-instructed persons who should initiate his subjects in Western lore. They returned practically alone; but Nicolo's son Marco accompanied them. They remained for seventeen years in the service of the Khan (1275-93), and Marco Polo has left a very celebrated account of his travels. This establishment of friendly feeling was followed by a definite mission of Franciscans, headed by John of Monte Corvino, who had already organised the missions in Persia. He was welcomed by Kublai's successor, and was allowed to preach. Despite the violent opposition of the Nestorians he made converts and built churches. In 1307 he became the first Archbishop of Cambaluc or Peking, while subsequently no less than ten suffragans were grouped under him. Scarcely less remarkable was the organisation in Persia of the archbishopric at Sultanyeh and six subordinate sees. But this development belongs almost entirely to the following period. CHAPTER XV GUELF AND GHIBELLINE. (II) [Sidenote: Honorius III (1216-27) and the Crusade.]