 The precursor of paper money (紙幣) known as "Flying cash" were issued by the Tang dynasty, however these bills of exchange could in no way be considered to be a form of paper money as they weren't meant to be a medium of exchange and were only negotiable between two distant points.The first true paper money in the world was issued under the Song dynasty, these were promissory notes issued by merchants in Sichuan known as the Jiaozi, under the reign of Emperor Zhenzong (997–1022) the government of the Song Dynasty granted a monopoly for the production of Jiaozi notes to sixteen wealthy merchants in Sichuan, as these merchants were slow to redeem their banknotes and inflation started affecting these private banknotes the government nationalised paper money in the year 1023 under the Bureau of Exchange.As these paper notes were backed by the government they were instantly successful and the people regarded them to be equally trustworthy as cash coins, other types of paper notes issued under the Song dynasty include the Huizi and the Guanzi.