Tang City Site was under Emperor Yang of Sui (r. 604–617), Yangzhou was the southern capital of China. It was called Jiangdu upon the completion of the Grand Canal until the fall of the Sui dynasty.By the mid 610s, a combination of fruitless attempts to conquer the Korean kingdom of Goguryeo, together with natural disasters and provincial unrest, ensured many people Emperor Yang had lost the legitimacy of his monarchy.