After a series of defeats by Wei Qing (the half-brother of Emperor Wu's favourite concubine) and Wei's nephew, Huo Qubing between 127 and 119 BC, the Xiongnu were expelled from the Ordos Desert and Qilian Mountains. As a result of these territorial acquisitions, the Han Dynasty successfully opened up the Northern Silk Road, allowing direct access to trade with Central Asia. This also provided a new supply of high-quality horse breeds from Central Asia, including the famed Ferghana horse (ancestors of the modern Akhal-Teke), further strengthening the Han army. Emperor Wu then reinforced this strategic asset by establishing five commanderies and constructing a length of fortified wall along the border of the Hexi Corridor, colonizing the area with 700,000 Chinese soldier-settlers.