128-7 Chinese general Wei Qing regains the Ordos for China from the Xiongnu and repairs the Shihuangdi frontier walls on the far side of the Yellow river.
Xiognu chanyu Modu encourages the Shanxi king to rebel, providing a route into Han territory. Han emperor Gaozu is defeated in battle and almost killed.
123-2 Wei Qing penetrates 250 km into Xiongnu territory, forcing Yizhe Chanyu to move his main camp north of the desert.
121 After a campaign by Chinese general Huo Qubing, the Xiongnu sub-kings of the left and right, fearing execution by Yizhe Chanyu, surrender with 40,000 men, although one, Hunye, kills the other, Xiutu, first. Ganzu and northern Shanxi become Chinese and Emperor Wudi settles 700,000 people there.
119 Huo Qubing pushes 800 km into Xiongnu territory, to the east of Ulaan Baatar, and kills 70,000 men of the King of the Left, then routs Yizhe Chanyu in central Mongolia, killing almost 20,000 more. The Xiongnu would never fully recover from these battles.
Han Wudi begins building watchtowers and signal towers along the Erzin Gol.
115 Jiuquan is made prefectural capital, followed by Wuwei, then Zhangye and Dunhuang (111 BCE). China gains access for the first time to the Western Regions.
108 Chinese general Zhao Ponu conquers Loulan and Jushi (Turfan), although Loulan wavers for 5 years.
109 Emperor Han Wudi invades and annexes Dian.
106-5 The Xiongnu move the royal residence to the upper reaches of the Orkhon.
103 Chinese general Renwen leads a punitive expedition against Loulan, and Han Wudi then builds walls and fortifications all the way to Kucha.
102 After an initial abortive attempt, 2 years earlier, Chinese general Li Guangli accepts the surrender of Fergana, and extracts a ransom of horses.
China, A History, John Keay, p 144
The History of Central Asia, The Age of the Silk Roads, Christoph Baumer, pp 10-29
Dian Kingdom, Wikipedia
Minyue, Wikipedia
Das Tarimbecken, Wikipedia
East Hemisphere in 100 BC, Talessman's Atlas
The Han empire is shown around its maximum extent. The date is approximate.