Under the succeeding Tang and Song dynasties, Chinese economy, technology, and culture entered a golden age. The Tang Empire retained control of the Western Regions and the Silk Road, which brought traders to as far as Mesopotamia and the Horn of Africa, and made the capital Chang'an a cosmopolitan urban center. However, it was devastated and weakened by the An Lushan Rebellion in the 8th century. In 907, the Tang disintegrated completely when the local military governors became ungovernable. The Song dynasty ended the separatist situation in 960, leading to a balance of power between the Song and Khitan Liao. The Song was the first government in world history to issue paper money and the first Chinese polity to establish a permanent standing navy which was supported by the developed shipbuilding industry along with the sea trade.