By the standards of the 14th century, the writing style of the man who called himself Sir John Mandeville is so informal as to be nearly chummy: "He who wants to pass over the sea to Jerusalem, may go by many ways, both by sea and by land depending on the countries he comes from; many ways come to a single end. But do not think I shall tell of all the towns and cities and castles that men shall go by, for then I must make too long a tale of it." Historians remain skeptical as to whether the author really did journey to the Holy Land and Egypt, or hire himself out as a soldier to the Great Khan of China. Whatever the case, it is indisputable that he is one of the first modern travel writers, as we have come to know the genre, and that his book was considered authoritative in matters geographical throughout Europe--consulted by Leonardo da Vinci and Christopher Columbus alike.