On February 4, 960, military leader Zhao Kuangyin became the first emperor of the Song Dynasty. The Song ruled China for more than 300 years. The Song Dynasty was notable for its contributions to government and science. Under the Song, China became the first government in the world to issue paper money (called jiaozi) on a national scale, allowing traders in far-flung portions of the empire to buy and sell goods at established prices. Scientists experimenting with magnetism were the first in the world to identify the concept of “magnetic north” by reading a compass. The first instances of moveable type are dated to Song Dynasty. Song military leaders were the first in the world to use gunpowder. Gunpowder, however, was not enough to ward off the powerful Mongol army led by Kublai Khan. The “Great Khan” conquered the Song and established the Yuan Dynasty throughout China in 1279.