The economy of the Song dynasty (960–1279) in China was the wealthiest economy in the world during its time. The dynasty moved away from the top-down command economy of the Tang dynasty (618-907) and made extensive use of market mechanisms as national income grew to be around three times that of 12th century Europe. The dynasty was beset by invasions and border pressure, lost control of North China in 1127, and fell in 1279. Yet the period saw the growth of cities, regional specialization, and a national market. There was sustained growth in population and per capita income, structural change in the economy, and increased technological innovation. Movable print, improved seeds for rice and other commercial crops, gunpowder, water-powered mechanical clocks, the use of coal as an industrial