Zheng He's western voyages, unprecedented in the history of the world, took place against a unique historical backdrop. The Yongle and Xuande reign periods of the early Ming Dynasty were times of intense social momentum. On the one hand, the Chinese people had always had a relationship with the ocean, while on the other, China enjoyed great domestic prosperity and highly developed commerce. Strengthening foreign relations and expanding maritime trade were vital to the Ming Dynasty's continued political, economic, and cultural growth. Within several decades of the founding of the Ming Dynasty, China had opened its doors to overseas exploration and trade and implemented a policy of peaceful foreign exchange, in accordance with the demands of the times. The great fleets led by Zheng He on his seven western voyages served as noteworthy goodwill envoys to the outside world.