At their height between the 2nd and 1st centuries BCE, the Xiongnu controlled approximately 3–5 million km², dominating the eastern Eurasian steppe as the primary rival of Han China. Their territory stretched from the Mongolian Plateau and the Gobi Desert in the east to parts of Central Asia in the west, from southern Siberia in the north to the northern frontier of China in the south. Known in Chinese records as the Xiongnu and increasingly identified by scholars with the Asian ancestors of the Huns who would later strike Europe under Attila, this nomadic confederation built its power on cavalry warfare, tribal alliances, and control of the steppe trade routes that would become the northern Silk Road.