Kublai-khan reigned supreme emperor of the Mongals from 1259 to 1294, in which last year he died at eighty years of age.  If, therefore, Nicolo and Maffei had set out upon their first journey in 1250, they must have arrived at the imperial residence of Cambalu, or Pekin, in 1255, at the latest, or four years before Kublai-khan ascended the throne.  Their first journey commenced while Baldwin II. was emperor of Constantinople, who reigned from 1234 to 1261.  The khan of Kiptschak, or the western division of the vast empire of the Mongals, at the time of this journey, was Bereke, who ruled from 1256 to 1266.  Holagu-khan, who was then at war with Bereke, did not begin to reign till 1258.  Hence it follows, that they could not have commenced their first journey at the very earliest before 1258, or 1259 rather; as it is not to be supposed that Holagu would enter upon a dangerous war in the first year of his reign.  Upon the whole, therefore, the date of 1260, for the commencement of the first journey, as already observed, is perfectly consistent with the chronology of history.

The year of their return to Venice, 1269, is agreed upon on all hands; and as Marco was born in the first year of their absence, he would then be about nine years of age.  Ramusio, who dates the commencement of the first journey in 1250, supposes Marco to have been fifteen years of age at the return of his father and uncle, which is absurd; as, if the era assumed by Ramusio were possibly true, he must then have been in his nineteenth year.

According to the opinion of Mr J. R. Forster, the commencement of the second journey in which Marco was engaged, must have been in 1271; and he founds this opinion on the circumstance, that Gregory IX. had then been elected pope, from whom they carried letters for Kublai-khan.  But it will appear from the travels themselves, that the three Polos had commenced their journey previously to the election of that sovereign pontiff, and that they were detained some time in Armenia, in consequence of an express sent after them for the purpose, that they might there wait for his final instructions.  They may, therefore, have commenced this second journey in 1270.  We only know, however, that they set out from Venice for a second journey into Tartary, soon after their return from the first, in 1269; and that they carried young Marco along with them.  On his appearance at the court of Cambalu, Kublai-khan took a fancy to the young Venetian, and caused him to be instructed in four of the principal languages which were spoken in the extensive dominions of the Mongals.  Marco was afterwards employed by the khan, for a considerable number of years, in several important affairs, as will appear in the relation of his travels.