The Xiongnu (Old Chinese: /qʰoŋ.nˤa/, Wade–Giles: Hsiung-nu), were a large confederation of Eurasian nomads  who dominated the Asian Steppe from the late 3rd century BCE to the late 1st century CE. Chinese sources from the 3rd century BC report them as having created an empire under Modu Chanyu, the supreme leader after 209 BC. This empire (209 BC — 93 AD) stretched beyond the borders of modern-day Mongolia. After defeating the previously dominant Yuezhi in the 2nd century BC, the Xiongnu became a dominant power on the steppes of central and eastern Asia. They were active in regions of what is now southern Siberia, Mongolia, Inner Mongolia, Gansu and Xinjiang. Relations between early adjacent Chinese dynasties to the south east and the Xiongnu were complex, with repeated periods of military conflict and intrigue, alternating with exchanges of tribute, trade, and marriage treaties.