Qing again launched from Dingxiang, but would fight a relatively inconclusive battle. Although he was able to kill/capture more than 10,000 Xiongnu soldiers, part of his vanguard forces, a 3,000-strong regiment commanded by generals Su Jian and Zhao Xin (a surrendered Xiongnu prince), encountered a Xiongnu force led by Chanyu Yizhixie (伊稚斜單于), and was outnumbered and annihilated. Zhao Xin defected on the field with his 800 ethnic Xiongnu subordinates, while Su Jian escaped after losing all his men in the desperate fighting. Showing compassion on Su Jian, Wei Qing spared him even though some advocates advised him to execute Su on the spot after court martial to enforce his commanding authority. Due to the loss of Su's detachment, Wei Qing troops did not earn any promotion, even though they scored more gains than losses. At this campaign, his nephew Huo Qubing distinguished himself in battle and was given his own command. The Battle of Mobei After Huo Qubing's successful campaigns in the Hexi Corridor, Xiongnu strategically retreated to north of the Gobi Desert, as the barren lands would serve as a natural barrier that was very difficult to overcome for the Han forces. However, in 119 BC, Emperor Wu decided to defy the odds and launched a massive expeditionary campaign across the desert. In this engagement, Emperor Wu broke the normal pattern of reaction against Xiongnu attacks by making a major excursion against Xiongnu's headquarters in the north of the Gobi Desert. This is known to history as the Mobei Campaign ("campaign of the desert's north"). Wei Qing and Huo Qubing were in command of the two main corps, each with 50,000 cavalrymen and 100,000 infantrymen/charioteers. Under Wei Qing's command were four other generals, namely Gongsun He, Zhao Yiji (趙食其), Cao Xiang (曹襄) and an elderly but very enthusiastic Li Guang. Contrary to the arrangements promised to Li Guang by Emperor Wu (where he would command the vanguard), Emperor Wu secretly told Wei Qing not to assign Li Guang to crucial missions due to Li's infamous history of "bad lucks". Wei Qing, after the army had already departed, merged Li Guang's forces with Zhao Yiji's and ordered them to take an eastern flanking route through a barren region. According to the historian Sima Qian, Wei Qing had done this to give his old friend Gongsun Ao, who had recently been stripped of his title, a chance to win a major