The second Qing Emperor of China (1662–1722). He extended the Qing empire by a series of military campaigns, subduing opposition to Manchu rule in southern China (1673–81), incorporating Taiwan into China for the first time in 1683, and personally leading a campaign into Outer Mongolia (1693). He opened certain ports to overseas traders and the Treaty of Nerchinsk (1689), established diplomatic contact with Russia. In 1692 he permitted Catholic missionaries to make converts and he employed Jesuits to teach astronomy and mathematics. He was renowned for his history of the Ming dynasty and an encyclopedia of literature.