Marco commanded a ship in a war against the rival city of Genoa. He was eventually captured and sentenced to a Genoese prison, where he met a fellow prisoner and writer named Rustichello. As the two men became friends, Marco told Rustichello about his time in Asia, what he'd seen, where he'd traveled and what he'd accomplished. His stories were soon committed to paper and eventually published as a book called The Description of the World, later known as The Travels of Marco Polo.