never heavy. This explains why corresponding latitudes of North America were fully glaciated during glacial periods of the Quaternary while Manchuria, though even colder, always remained too dry to form glaciers – a state of affairs enhanced by stronger westerly winds from the surface of the ice sheet in Europe. History Early history Manchuria was the homeland of several ethnic groups, including Manchu, Mongols, Koreans, Nanai, Nivkhs, Ulchs, Hui and possibly Turkic peoples and ethnic Han Chinese in southern Manchuria. Various ethnic groups and their respective kingdoms, including the Sushen, Donghu, Xianbei, Wuhuan, Mohe, Khitan and Jurchens, have risen to power in Manchuria. Various Koreanic kingdoms such as Gojoseon (before 108 BCE), Buyeo (2nd century BCE to 494 CE) and Goguryeo (37 BCE to 688 CE) also became established in large parts of this area. The Han dynasty (202 BCE to 9 CE and 25 to 220 CE), the Cao Wei dynasty (220–266), the Western Jin dynasty (266–316), the Tang dynasty (618–690 and 705–907) and some other minor kingdoms of China established control in parts of Manchuria and in some cases tributary relations with peoples in the area. Parts of northwestern Manchuria came under the control of the First Turkic Khaganate of 552–603 and of the Eastern Turkic Khaganate of 581–630. Early Manchuria had a mixed economy of hunting, fishing, livestock, and agriculture. With the Song dynasty (960-1269) to the south, the Khitan people of Inner Mongolia created the Liao dynasty (916-1125) and conquered Outer Mongolia and Manchuria, going on to control the adjacent part of the Sixteen Prefectures in Northern China as well. The Liao dynasty became the first state to control all of Manchuria. In the early 12th century the Tungusic Jurchen people, who were Liao's tributaries, overthrew the Liao and formed the Jin dynasty (1115–1234), which went on to control parts of Northern China and Mongolia after a series of successful military campaigns. During the Mongol Yuan dynasty rule of China (1271–1368), Manchuria was administered as Liaoyang province. In 1375 Naghachu, a Mongol official of the Mongolia-based Northern Yuan dynasty of 1368–1635 in Liaoyang province invaded Liaodong, but later surrendered to the Ming dynasty in 1387. In order to protect the northern border areas, the Ming dynasty decided to "pacify" the Jurchens in order to deal with its problems with Yuan remnants along its northern border. The Ming solidified control over Manchuria under the Yongle Emperor (),