 Later, in the 13th century, the middle-Amur and the Zeya River basin area became the homeland of the Daurs and (further south) the Duchers.The ancestors of the Daurs are thought to be closely related to the Khitans and the Mongols, while the Duchers may have been a branch of the Jurchen people, later known as the Manchus.The area was conquered by the Manchus in 1639–1640, after defeating the Evenk Federation led by Bombogor, it was returned to the Qing Dynasty in the Treaty of Nerchinsk and annexed by Russia in 1858 by the Treaty of Aigun between Russia and Qing Dynasty.