The Manchus were a non-Chinese people living in the northeastern peripheral zone of Chinese civilization. They had adopted the Chinese form of empire and bureaucracy in their capital at Mukden in the early seventeenth century, before advancing toward China proper. Invited by the Chinese to lend their aid in a civil war, the Manchus found themselves excelling in effectiveness and leadership, which soon led them to conquer the whole country. The numerical disproportion between Chinese and Manchus was such that the conquerors would never have taken over the Empire and founded a new dynasty (the Ch'ing) had they not been assisted by large numbers of Chinese. On the other hand, the spectacular terrorism of the Manchu cavalry was a potent weapon, and the Manchus did not feel that they owed their throne entirely to the Chinese. They were in the anomalous position of half-conquerors, a people coming into China partly as aliens and partly as the new leaders of the Chinese. At the very beginning of their rule (commonly dated 1644) they had to decide on a policy to determine their relations with the Chinese: Should they allow their people to mingle with and disappear into the vast Chinese masses, or should they attempt a policy of racial separateness to keep their blood clear of Chinese dilution? Underlying this question there was the even more practical one: Should the Manchus rule China simply as another imperial house, or should they attempt to maintain their status as a racially separate caste of conquerors? There is a Chinese legend which tells of a high minister of state, a Chinese in the service of the Manchu conquerors, who saw no remedy from the oppression of China in his own generation, but who nevertheless worked with craftily concealed patriotism to sow the undoing of the house of the Ch'ing. He recommended to the Manchus that they keep their fighting men from demoralization by ordaining that no Manchu warrior should enter any trade or profession but those of warfare and public administration, and that they should guard the ancient heritage of their valiant blood by making miscegenation a crime. Thus he schemed to stiffen the Manchu monarchy in a position of unbounded arrogance, so that a few generations of peace would find its armies sloven, atrophied, and useless, and its people still alien to the Chinese. With neither military power to overawe the masses nor popular affection to uphold their foreign-rooted dynasty, they were bound to go down; all this, the legend tells, the Chinese adviser who lived and died with high Manchu honors clearly foresaw. Actually the Manchus did move in such a direction, and with the prophesied results.