Manchuria is traditionally the homeland of peoples that have invaded and sometimes ruled N China. Among the most important of these tribes were the Tungus, Eastern Turks, Khitan, and Jurchen. It was the home of the Manchu conquerors of China. The Manchus tried to keep Manchuria an imperial preserve by limiting Chinese immigration. During the 20th cent., however, emigration to Manchuria from the adjacent provinces was heavy, and the population is now predominantly Chinese.