Marco Polo was in China
For those in the mood for some light reading, here's Hans Ulrich Vogel's great tome, "Marco Polo was in China: New Evidence from Currencies, Salts and Revenues," free to read online: https://books.google.ca/books?id=Ydo_9TEmuVQC&lpg=PP1&pg=PP1#v=onepage&q&f=false
Vogel thoroughly shows how Marco Polo's mentions of currency and the important salt trade are not only accurate, but demonstrate first hand experience which could not have been gained from western sources. It was popular in the late 1990s to argue that Polo made it only as far as Constantinople or the shores of the Caspian Sea, writing his works from Persian travel guides, but the matter has been essentially settled. To paraphrase Stephen Haw (I believe), if Marco Polo was a liar, he was an incredibly meticulous one. Stephen Haw is another historian who has demonstrated that long unidentified location, flora and fauna names are in fact identifiable, and has done so himself, for example in his own "Marco Polo's China: A Venetian in the Realm of Kublai Khan." The majority of the data Polo reports would have been exceptionally difficult to acquire without firsthand experience.
The doubt in Polo's work is due to a few reasons: one is that sheer number of extant manuscripts. Translations upon translations, scribal errors (especially in an age before the printing press), someone changing and adding to it (Polo released an edited edition himself at one point) not to mention that Polo himself did not write the work. Rather, while imprisoned by the Genoese, Polo dictated it (from his own notes) while his 'cellmate,' Rustichello, a writer of popular romances, wrote it down. Rustichello copied some sections from his earlier works, certainly to make things 'readable,' and likely encouraged changes, such as making Kublai appear more open to Christianity than he likely actually was. Further, Polo is at times recounting events which happened to him over 20 years prior: at such points, human memory can prove faulty, and mistakes slip in. A lot of the controversy around Polo's work has also come from modern anachronism. For instance, common points were that Polo never mentioned the Great Wall of China or footbinding. These complaints arose in the 18th and 19th centuries, and generally came from authors with little knowledge of China, Mongolia and their histories. The Great Wall of China as it exists today was not built until the Ming Dynasty, centuries after Polo's departure. The walls of earlier dynasties were in Polo's time eroded lumps of rammed earth, hardly worth mentioning. Further, why note a wall which had played no role in preventing the Mongol conquest of China? Footbinding was practice among Chinese elites, but how common is debated. Polo stayed largely with Mongols, who did not practice it.
Another common argument is that Polo presents his father and uncle as responsible for introducing the traction catapult to the Mongols to help in the siege of Xiangyang, which would have happened while they were not in China, and is recorded elsewhere as being brought by Muslim Engineers (we might even asks why merchants would even have the knowledge to construct siege weapons?) I imagine this was a case of someone deciding that Christian audiences didn't want to hear how Muslims aided the Mongols, and a bigger role was thus given to Polo's family to make them seem more significant. Likewise for the assertions that Polo was a governor of a town, which is only mentioned in a few manuscripts, and seems due to scribal errors and later exaggeration. In regards to Chinese sources to not mentioning Polo, it must be noted that they don't ever mention any Europeans by names, and even if they did they were unlikely to use his surname (as Haw noted, if Marco Polo took a Turkic or Mongol name to go by as well, we would have no way of knowing). To the Chinese, Polo was just another foreigner in a government full of foreigners and barbarians.
The current scholarly consensus is that Marco Polo was in Kublai's empire, but we can still argue over details. What was his exact role? (an emissary of some sort? involved in the salt trade?) at which points is he exaggerating (for instance, how close was he with Kublai really?) Some places he mentions were far off his trail, is he intending to imply that he visited them all? At times he falls prey to believing local legends or beliefs, (such as the story that the Caliph of Baghdad converted to Christianity before his death!) but the core of the document is a trustworthy, if at times flawed, source, but one best to read with the notes of an expert to decipher it at times.
