The invasion began in October 1936, with the main force consisting of Prince De Wang's and Wang Ying's troops, while Li Shouxin and his detachment remained in reserve. The first contact between Nationalist and Inner Mongolian forces occurred at the town of Hongort on 14 November. A large attack was launched by the Mongolians the next day, but they were repulsed. Over the next couple of days they continued to launch assaults against the city's walls, but were beaten back and sustained considerable casualties. The Mongolian troops did not lack courage but were not adequately trained for that kind of assault. A final attack was attempted on 16 November during a snowstorm but it was also beaten back by the Chinese defenders.