One popular belief holds that after Zheng's voyages, China turned away from the seas and underwent a period of technological stagnation. Although historians such as John Fairbank and Joseph Needham popularized this view in the 1950s, most current historians of China question its accuracy. that Chinese ships continued to dominate Southeast Asian commerce until the 19th century and that active Chinese trading with India and East Africa continued long after the time of Zheng. The travels of the Chinese junk Keying to the United States and England between 1846 to 1848 testify to the power of Chinese shipping until the 19th century.Although the Ming Dynasty did ban shipping for a few decades with the Hai jin edict, they eventually lifted this ban. The alternative view cites the fact that by banning ocean going shipping the Ming (and later Qing) dynasties forced countless numbers of people into blackmarket smuggling. The lack of an ocean going navy then left China highly vulnerable to the Waku (wakou) pirates that ravaged China in the 16th century.Starting in the early 15th century China experienced increasing pressure from resurgent Mongolian tribes from the north. In recognition of this threat and possibly to move closer to his family's historical geographic power base, in 1421 the emperor Yongle moved the capital north from Nanjing to present-day Beijing. From the new capital he could apply greater imperial supervision to the effort to defend the northern borders. At considerable expense, China launched annual military expeditions from Beijing to weaken the Mongolians. The expenditures necessary for these land campaigns directly competed with the funds necessary to continue naval expeditions.In 1449 Mongolian cavalry ambushed a land expedition personally led by the emperor Zhengtong less than a day's march from the walls of the capital. In the Battle of Tumu Fortress the Mongolians wiped out the Chinese army and captured the emperor. This battle had two salient effects. First, it demonstrated the clear threat posed by the northern nomads. Second, the Mongols caused a political crisis in China when they released Zhengtong after his half-brother had proclaimed himself the new Jingtai emperor. Not until 1457 did political stability return when Zhengtong recovered the throne. Upon his return to power China abandoned the strategy of annual land expeditions and instead embarked upon a massive and expensive expansion of the Great Wall of China. In this environment, funding for naval expeditions simply did not happen.More fundamentally, unlike the later naval expeditions conducted by European nations.
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鄭和下西洋
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明代沈度作《瑞應麒麟圖》，描繪永樂十二年（1414年}榜葛剌國表進麒麟
第一次下西洋
永樂三年六月十五（1405年7月11日）從南京龍江港啟航，經太倉出海，永樂五年九月初二（1407年10月2日）回國。第一次下西洋人數據載有27800人。
第二次下西洋
永樂五年九月十三日（1407年10月13日）出發，到達汶萊、泰國、柬埔寨、印度等地，在錫蘭山迎請佛牙，隨船帶回，永樂七年夏（1409年）回國。第二次下西洋人數據載有27000人。
第三次下西洋
永樂七年九月（1409年10月）從太倉劉家港啟航，姚廣孝、費信、馬歡等人會同前往，到達越南、馬來西亞、印度等地，回國途中訪錫蘭山，永樂九年六月十六（1411年7月6日）回國。
第四次下西洋
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明鈔本 馬歡：《瀛涯勝覽》
永樂十一年十一月（1413年11月）出發，隨行有通譯馬歡，繞過阿拉伯半島，首次航行東非麻林迪，永樂十三年七月初八（1415年8月12日）回國。同年11月，麻林迪特使來中國進獻「麒麟」（即長頸鹿）。4第四次下西洋人數據載有27670人。
第五次下西洋
永樂十五年五月（1417年6月）出發，隨行有蒲壽庚的後代蒲日和，途經泉州，到占城、爪哇，最遠到達東非木骨都束、卜喇哇、麻林等國家，永樂十七年七月十七（1419年8月8日）回國。
第六次下西洋
永樂十九年正月三十日（1421年3月3日）出發，往榜葛刺（孟加拉），史載「於鎮東洋中，官舟遭大風，掀翻欲溺，舟中喧泣，急叩神求佑，言未畢，……風恬浪靜」，中道返回，永樂二十年八月十八（1422年9月2日）回國。永樂二十二年，明成祖去世，仁宗朱高熾即位，以經濟空虛，下令停止下西洋的行動。
第七次下西洋
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寶船從龍江關出水
宣德五年閏十二月初六（1431年1月從龍江關（今南京下關）啟航，返航後，鄭和因勞累過度於宣德八年（1433年）四月初在印度西海岸古里去世，船隊由太監王景弘率領返航，宣德八年七月初六（1433年7月22日）返回南京。第七次下西洋人數據載有27550人。
One popular belief holds that after Zheng's voyages, China turned away from the seas and underwent a period of technological stagnation. Although historians such as John Fairbank and Joseph Needham popularized this view in the 1950s, most current historians of China question its accuracy. that Chinese ships continued to dominate Southeast Asian commerce until the 19th century and that active Chinese trading with India and East Africa continued long after the time of Zheng. The travels of the Chinese junk Keying to the United States and England between 1846 to 1848 testify to the power of Chinese shipping until the 19th century.Although the Ming Dynasty did ban shipping for a few decades with the Hai jin edict, they eventually lifted this ban. The alternative view cites the fact that by banning ocean going shipping the Ming (and later Qing) dynasties forced countless numbers of people into blackmarket smuggling. The lack of an ocean going navy then left China highly vulnerable to the Waku (wakou) pirates that ravaged China in the 16th century.Starting in the early 15th century China experienced increasing pressure from resurgent Mongolian tribes from the north. In recognition of this threat and possibly to move closer to his family's historical geographic power base, in 1421 the emperor Yongle moved the capital north from Nanjing to present-day Beijing. From the new capital he could apply greater imperial supervision to the effort to defend the northern borders. At considerable expense, China launched annual military expeditions from Beijing to weaken the Mongolians. The expenditures necessary for these land campaigns directly competed with the funds necessary to continue naval expeditions.In 1449 Mongolian cavalry ambushed a land expedition personally led by the emperor Zhengtong less than a day's march from the walls of the capital. In the Battle of Tumu Fortress the Mongolians wiped out the Chinese army and captured the emperor. This battle had two salient effects. First, it demonstrated the clear threat posed by the northern nomads. Second, the Mongols caused a political crisis in China when they released Zhengtong after his half-brother had proclaimed himself the new Jingtai emperor. Not until 1457 did political stability return when Zhengtong recovered the throne. Upon his return to power China abandoned the strategy of annual land expeditions and instead embarked upon a massive and expensive expansion of the Great Wall of China. In this environment, funding for naval expeditions simply did not happen.More fundamentally, unlike the later naval expeditions conducted by European nations.