The missionary work was less effective. The missionaries penetrated by the old trade routes from Canton and Macao into the province of Kiangsi and then into Nanking. Kiangsi and Nanking were their chief centres. They soon realized that missionary activity that began in the lower strata would have no success; it was necessary to work from above, beginning with the emperor, and then, they hoped, the whole country could be converted to Christianity. When later the emperors of the Ming dynasty were expelled and fugitives in South China, one of the pretenders to the throne was actually converted--but it was politically too late. The missionaries had, moreover, mistaken ideas as to the nature of Chinese religion; we know today that a universal adoption of Christianity in China would have been impossible even if an emperor had personally adopted that foreign faith: there were emperors who had been interested in Buddhism or in Taoism, but that had been their private affair and had never prevented them, as heads of the state, from promoting the religious system which politically was the most expedient--that is to say, usually Confucianism. What we have said here in regard to the Christian mission at the Ming court is applicable also to the missionaries at the court of the first Manchu emperors, in the seventeenth century. Early in the eighteenth century missionary activity was prohibited--not for religious but for political reasons, and only under the pressure of the Capitulations in the nineteenth century were the missionaries enabled to resume their labours. 14 _External and internal perils_ Towards the end of the reign of Wan-li, about 1620, the danger that threatened the empire became more and more evident. The Manchus complained, no doubt with justice, of excesses on the part of Chinese officials; the friction constantly increased, and the Manchus began to attack the Chinese cities in Manchuria. In 1616, after his first considerable successes, their leader Nurhachu assumed the imperial title; the name of the dynasty was Tai Ch'ing (interpreted as "The great clarity", but probably a transliteration of a Manchurian word meaning "hero"). In 1618, the year in which the Thirty Years War started in Europe, the Manchus conquered the greater part of Manchuria, and in 1621 their capital was Liaoyang, then the largest town in Manchuria.