This transfer of the capital to the north, as the result of the victory of the military party and Buddhists allied to them, produced a new element of instability: the north was of military importance, but the Yangtze region remained the economic centre of the country. The interests of the gentry of the Yangtze region were injured by the transfer. The first Ming emperor had taken care to make his court resemble the court of the Mongol rulers, but on the whole had exercised relative economy. Yung-lo (1403-1424), however, lived in the actual palaces of the Mongol rulers, and all the luxury of the Mongol epoch was revived. This made the reign of Yung-lo the most magnificent period of the Ming epoch, but beneath the surface decay had begun. Typical of the unmitigated absolutism which developed now, was the word of one of the emperor's political and military advisors, significantly a Buddhist monk: "I know the way of heaven. Why discuss the hearts of the people?"
After the collapse of Mongol rule in Indo-China, partly through the simple withdrawal of the Mongols, and partly through attacks from various Chinese generals, there were independence movements in south-west China and Indo-China. In 1393 wars broke out in Annam. Yung-lo considered that the time had come to annex these regions to China and so to open a new field for Chinese trade, which was suffering continual disturbance from the Japanese. He sent armies to Yünnan and Indo-China; at the same time he had a fleet built by one of his eunuchs, Cheng Ho. The fleet was successfully protected from attack by the Japanese. Cheng Ho, who had promoted the plan and also carried it out, began in 1405 his famous mission to Indo-China, which had been envisaged as giving at least moral support to the land operations, but was also intended to renew trade connections with Indo-China, where they had been interrupted by the collapse of Mongol rule. Cheng Ho sailed past Indo-China and ultimately reached the coast of Arabia. His account of his voyage is an important source of information about conditions in southern Asia early in the fifteenth century. Cheng Ho and his fleet made some further cruises, but they were discontinued. There may have been several reasons, (1) As state enterprises, the expeditions were very costly. Foreign goods could be obtained more cheaply and with less trouble if foreign merchants came themselves to China or Chinese merchants travelled at their own risk. (2) The moral success of the naval enterprises was assured. China was recognized as a power throughout southern Asia, and Annam had been reconquered. (3) After the collapse of the Mongol emperor Timur, who died in 1406, there no longer existed any great power in Central Asia, so that trade missions from the kingdom of the Shahruk in North Persia were able to make their way to China, including the famous mission of 1409-1411. (4) Finally, the fleet would have had to be permanently guarded against the Japanese, as it had been stationed not in South China but in the Yangtze region. As early as 1411 the canals had been repaired, and from 1415 onward all the traffic of the country went by the canals, so evading the Japanese peril. This ended the short chapter of Chinese naval history.