From the Mongols, the Ming rulers had inherited extensive maritime contacts and technology. During Mongol rule, large Chinese cargo ships plied the oceans around China, including a regular run of grain from the south, along the coast, to the north. And Chinese ships traded through southeast Asia to the island of Lanka (Sri Lanka) and to India.
The Ming dynasty did not maintain this trade, Zheng He's expedition, beginning in 1405, being made not for the sake of trade but for geographical exploration and diplomacy - an expedition with sixty-three ships and 27,000 men. Six more expeditions led by Zheng followed, the last one in 1433 under the emperor Xuan-de. The expeditions reached Surabaya at the island of Java, and they reached India and then Mogadishu on the coast of Africa, Hormuz at the Persian Gulf, and up the Red Sea to Jeddah. Gifts were exchanged, and rare spices, plants and animals, including a giraffe, were brought back to China.
China had the world's greatest navy, with an estimated 317 ships, some of them 440 feet long and 180 feet wide, ships with four to nine masts that were as high as ninety feet, and with crews as large as five hundred. But in China interest in a great navy and merchant shipping was overshadowed by concern about military defenses on land. Attempts to control Annam failed and were expensive. In mid-century the Mongols were making border raids and appeared to the Chinese as an even greater threat. Also, with independence from Mongol rule, Confucian influence had increased at court. Confucian scholars were filling the ranks of senior officialdom and remained hostile to commerce and foreign contacts. The Confucianists had little or no interest in seeing China develop into a great maritime trading power.
In the wake of Mongol rule, China's leaders were eager to restore things Chinese, and that included shipping on China's canals - which had gone into disrepair under the Mongols. They saw internal trade as enough. The government ended its sponsorship of naval expeditions, and, in the spirit of isolationism, the government outlawed multi-masted ships leaving China. The development of world maritime trade was left to others.
