The Mongols in Persia tried to introduce paper money, which worked very well within the older parts of the Mongol empire and China, but the merchants resisted and the Mongol governor was not confident of being able to put down an uprising so he withdrew the paper money. The success of paper money is contingent on a strong central government. In the older parts of the empire refusal to accept the official paper money was punishable by death - a punishment the Mongols generally eschewed.

"It is not necessary to have hope in order to persevere."