Ordos Desert
Liaison among the dynasty and groups of herdsmen relied on mutual economic and military benefits. As the Northern Xiongnu, the masters of the Mongolian steppes and mortal enemy of the [[Han dynasty]], were still potent enough during the reigns of [[Emperor Ming of Han|Emperor Ming]], [[Emperor Zhang of Han|Emperor Zhang]] and [[Emperor He of Han|Emperor He]] (58–105) to keep the volatile alliance intact, the Eastern Han dynasty enjoyed the most prosperous years of its almost 200 years of existence. Even fragments of the Northern Xiongnu migrated well within the border to the Xihe plain, west of the [[Yellow River]] and south of the [[Ordos Desert]]).