Marco Polo first set out when he was 17. He was accompanied by his uncle and his father. He was sent out on trips by a ruler to look out for the people and rule over them. He spend a lot of his time as a tax collector and traveler
Years later, he got captured in battle by Venice's arch rival Genoa. He went to prison and met Rustichello of Pisa whom he would soon collaborate with.
In prison, they collaborated on a manuscript called "Description of the World". Notes taken during his adventures helped him describe Kublai Khan, his palaces, and other things he saw. None of this had appeared in Europe. This all made him famous.