Nanning, meaning "South Tranquility," is the capital of the Guangxi Zhuang Autonomous Region in southern China. It is known as the "Green City" because of its abundance of lush tropical foliage. In 589 the Jinxing commandery was dissolved, and the county was renamed Xuanhua. Under the Tang dynasty (618-907) the prefecture of Yong) was established there; it was garrisoned to control the non-Chinese districts in Guangxi and on the Yunnan-Guizhou provincial border. In the mid-9th century the Tang and the Yunnan state of Nanzhao fought over it, and after 861 it was briefly occupied by Nanzhao. It remained a frontier prefecture throughout the Song dynasty (960 to 1279), being the scene of a rebellion led by Nong Zhigao in 1052 and thereafter a garrison town.