Passage: The idea of using a durable lightweight substance as evidence of a promise to pay a bearer on demand originated in China during the Han Dynasty in 118 BC, and was made of leather. Although Carthage was purported to have issued bank notes on parchment or leather, at least before the city's destruction in 146 BC, making Carthage the oldest known user of lightweight promissory notes. The first known banknote was first developed in China during the Tang and Song dynasties, starting in the 7th century. Its roots were in merchant receipts of deposit during the Tang Dynasty (618 -- 907), as merchants and wholesalers desired to avoid the heavy bulk of copper coinage in large commercial transactions. During the Yuan Dynasty, banknotes were adopted by the Mongol Empire. In Europe, the concept of banknotes was first introduced during the 13th century by travelers such as Marco Polo, with European banknotes appearing in 1661 in Sweden.

Question: Based on this passage, when was paper money first used in europe?
Steam of consciousness below:
The important part for answering this question is: In Europe, the concept of banknotes was first introduced during the 13th century by travelers such as Marco Polo, with European banknotes appearing in 1661 in Sweden.
So, the answer is 1661.