The Tang dynasty and Chang'an

A new dynasty unites China after long fragmentation and holds it for nearly three centuries. The capital Chang'an is laid out on a grid of streets and ringed with a wall; about a million people live there, and in its markets trade Sogdians, Persians, Arabs and Japanese. Buddhist monasteries stand alongside a Nestorian church and Zoroastrian shrines. The civil service examination becomes the accustomed road upward, and the poems of Li Bai and Du Fu are learned by heart to this day. The rebellion of the general An Lushan in 755 breaks the dynasty's strength, and the last decades of Tang pass in turmoil.