Economic- Comparison Mongols provided security along the Silk Road. Increased trade, disease merchants, were safe, Mongols collected taxes, caught stealing=death. The Mongol expansion throughout the Asian continent from around 1207 to 1360 helped bring political stability and re-establish the Silk Road (via Karakorum). It also brought an end to the Islamic Caliphate's monopoly over world trade. Because the Mongols had dominated the trade routes, it allowed more trade to come in and out of the region. Merchandise that did not seem valuable to the Mongols was often seen as very valuable by the west. As a result, the Mongols received in return a large amount of luxurious goods from the West. However, they never abandoned their nomadic lifestyle. Soon after Genghis Khan died, the Silk Road was in the hand of Genghis Khans' daughters.Paper currency was a by-product of Chinese block-printing. It started in Tang but not until Song dynasty that it became institutionized as a governmental policy. It had two main advantages over money made out of silver, gold, copper or iron: It was easier to carry around and the copper and iron could be saved for use in everyday objects. Names and seals were printed and written on paper money by the government officials who issued it. Unfortunately no written documents exist today which enable us to know how this system of paper currency actually functioned prior to the Yuan period. When Maro Polo traveld to China in the 13th century, he was so impressed by paper money that he described how it was made, used and valued. Paper money was not used in Europe until the 17th century.Paper money began with the "flying cash" of the Tang (618-907) dynasty around 800. The Tang government considering the inconvenience of shipping cash to distant areas where government purchases were made, paid local merchants with money certifiactes called "flying cash", because of its tendency to blow away. These certificates bearing different amounts of money could be converted into hard cash on demand at the capital. Since they were transferable, they were exchanged among merchans almost like currency."Flying cash" was not meant to be currency and its circulation was rather limited. The Persian Royal Road was an ancient highway reorganized and rebuilt by the Persian king Darius the Great (Darius I) of the Achaemenid Empire in the 5th century BC.[1] Darius built the road to facilitate