While at Karakorum, Rubruquis collected many interesting documents relating to the Chinese, their customs, literature, &c.; then leaving the capital of the Mongols, he returned by the same route as he had come, as far as Astrakhan; but there he branched to the south and went to Syria with a Turkish escort, which was rendered necessary by the presence of tribes bent on pillage. He visited Derbend, and went thence by Nakshivan, Erzeroum, Sivas, Caesarea, and Iconium, to the port of Kertch, whence he embarked for his own country. His route was much the same as that of Carpini, but his narrative is less interesting, and the Belgian does not seem to have been gifted with the spirit of observation which characterized the Italian monk. With Carpini and Rubruquis closes the list of celebrated travellers of the thirteenth century, but we have the brilliant career of Marco Polo now before us, whose travels extended over part of the thirteenth and fourteenth centuries. CHAPTER IV. MARCO POLO, 1253-1324. I. The interest of the Genoese and Venetian merchants in encouraging the exploration of Central Asia--The family of Polo, and its position in Venice--Nicholas and Matteo Polo, the two brothers--They go from Constantinople to the Court of the Emperor of China--Their reception at the Court of Kublai-Khan--The Emperor appoints them his ambassadors to the Pope--Their return to Venice--Marco Polo--He leaves his father Nicholas and his uncle Matteo for the residence of the King of Tartary--The new Pope Gregory X.--The narrative of Marco Polo is written in French from his dictation, by Rusticien of Pisa. The Genoese and Venetian merchants could not fail to be much interested in the explorations of the brave travellers in Central Asia, India, and China, for they saw that these countries would give them new openings for disposing of their merchandise, and also the great benefit to be derived by the West from being supplied with the productions of the East. The interests of commerce stimulated fresh explorations, and it was this motive that actuated two noble Venetians to leave their homes, and brave all the fatigue and danger of a perilous journey. These two Venetians belonged to the family of Polo, which had come originally from Dalmatia, and, owing to successful trading, had become so opulent as to be reckoned among the patrician families of Venice. In 1260 the two brothers, Nicholas and Matteo, who had lived for some years in Constantinople, where they had established a branch house, went to the Crimea, with a considerable stock of precious stones, where their eldest brother, Andrea Polo, had his place of business. Thence, taking a north-easterly direction and crossing the country of the Comans, they reached the camp of Barkai-Khan on the Volga. This Mongol prince received the two merchants very kindly, and bought all the jewels they offered him at double their value.