Emperor Xuan was a capable administrator , and his Kaiyuan Era is often compared with the earlier Zhenkuan era in efficiency of administration .
The height of Tang prosperity came during the Kaiyuan Era of Emperor Xuanzong of Tang , who expanded Tang influence westward to the Aral Sea .
Emperor Xuan was a capable administrator , and his Kaiyuan   is often compared with the earlier Zhenkuan era in efficiency of administration .
The height of Tang prosperity came during the Kaiyuan Era of Emperor Xuanzong of Tang , who expanded Tang influence westward to the Aral Sea .