During their stay in the East, Marco, his father, and his uncle acquired great wealth in jewels and gold. Khubilai Khan was reluctant to let his visitors return to Venice. However, they finally commenced their arduous journey home when Khubilai, in 1292, allowed them to escort a Mongol princess to Iran where she was to be wed. They endured great hardship on the return journey, including the deaths of many of their companions. As soon as they left Mongol jurisdiction, in Trebizond, they were robbed of much of their wealth. They finally arrived in Venice in 1295, to the surprise of relatives and friends who had thought them long dead. Some time after 1298, Marco was captured and imprisoned during a regional war between Venice and its chief trade rival, Genoa. By a fortunate coincidence, his cellmate was one Rustichello of Pisa, a writer of romances and chivalric lore. The story of exotic places and customs that Marco dictated to his fellow prisoner, which he titled A Description of the World, became one of the most popular books in medieval Europe. Many did not believe the stories, but others were inspired, including Christopher Columbus, who owned a copy of Marco's book.