Trade goods from the east
When Marco came back to Europe in 1295, he was the most traveled person of his age. But back in Italy he was taken prisoner during a sea battle. Luckily, he was locked in a cell with a curious writer who wrote his travel stories in a book, which became a bestseller when Marco was released.
After reading II Milione (A Million), Europeans became more interested in the Far East, especially in its gold, spices, perfume and silk. Spices like pepper, nutmeg or cinnamon were used to flavour food, but also as a medicine. Silk was used to make fancy clothes.