After a period of relative disunity, China was reunified by the Sui dynasty in 581 and under the succeeding Tang dynasty (618–907) China entered a Golden Age. The Tang Empire competed with the Tibetan Empire (618–842) for control of areas in Inner and Central Asia. The Tang dynasty eventually splintered, however, and after half a century of turmoil the Song dynasty reunified China, when it was, according to William McNeill, the "richest, most skilled, and most populous country on earth". Pressure from nomadic empires to the north became increasingly urgent. By 1142, North China had been lost to the Jurchens in the Jin–Song Wars, and the Mongol Empire conquered all of China in 1279, along with almost half of Eurasia's landmass. After about a century of Mongol Yuan dynasty rule, the ethnic Chinese reasserted control with the founding of the Ming dynasty (1368).