During the "Taoism era", China was able to maintain peace with Xiongnu by paying tribute and marrying princesses to them. During this time, the dynasty's goal was to relieve the society of harsh laws, wars, and conditions from both the Qin Dynasty, external threats from nomads, and early internal conflicts within the Han court. The government reduced taxation and assumed a subservient status to neighboring nomadic tribes. During this era, the government reduced its role in civilian lives (traditional Chinese: 與民休息; simplified Chinese: 与民休息; pinyin: yǔ mín xiūxi) and initiating a period of stability known as the Rule of Wen and Jing (Chinese: 文景之治; pinyin: Wén-Jǐngzhīzhì), named after the two Emperors of this particular era. However, under Emperor Wu, who reigned over one of the most prosperous periods of the Han Dynasty, the Empire was able to reassert its power. At its height, Han China incorporated present day Qinghai, Gansu, and northern Vietnam into its territories. The state mounted military expeditions into Siberian lands beyond Lake Baikal in the northern extremities and established military bases on the shores of the Caspian Sea at its western extremity.