Han Wudi (Han Wu-ti), the “Martial Emperor.” During his long reign, from 141 to 87 B.C., the boundaries and influence of the Chinese empire were greatly extended through a series of military campaigns. The policy of expansionism was primarily directed against the Xiongnu (Hsiung-nu), the name given to various Central Asian nomadic tribal groups of the period. The Xiongnu (sometimes inaccurately identified with the Huns) pressured Han northern borders throughout the duration of the dynasty, but during Han Wudi’s reign Chinese armies of up to 150,000 men destroyed Xiongnu power south of the Gobi desert and penetrated deep into Central Asia, in part to protect the trading caravans carrying surplus silk from China. At this time Chinese culture also began to take root in the territories of modern Korea and Vietnam.