As trade was an important source of wealth for the Yue tribes of coastal China, the region south of the Yangtze River attracted the attention of Emperor Qin Shi Huang, and he undertook a series of military campaigns to conquer it. Lured by its temperate climate, fertile fields, maritime trade routes, relative security from warring factions to the west and northwest, and access to luxury tropical products from Southeast Asia, the emperor sent armies to conquer the Yue kingdoms in 221 BCE. Military expeditions against the region were dispatched between 221 and 214 BCE. It would take five successive military excursions before the Qin finally defeated the Yue in 214 BCE.