When were Liaodong and Hetao captured by Qidan?

The ruling center of the Tang dynasty in the northeast was transferred to western Liaoning shortly after the demise of Koguryo. After the Anshi Rebellion, the vast area of Liaodong was basically a political blank area with a sparse population. Only Liaoyang, Liaoning Province established Dongping County in the later period of Bohai State. In 926 AD, Qidan destroyed the Bohai Sea, and in 928, Ye Ludeguang promoted Dongping County to Nanjing, the Qidan country, and immigrated to Liaodong from the hometown of Bohai Sea in the north to enrich this place. From then on, the whole Liaodong became the ruling area of Qidan. At the end of the Tang Dynasty and the beginning of the Five Dynasties, Tiandejun (Tuchengzi, Wuliangsuhai, Inner Mongolia) was located in the west of Hetao Plain, and Zhenwu Army (Tuchengzi, northwest of Hohhot and Linger, Inner Mongolia) was located in the east. In 9 16 AD, Lu Ye Abao made a westward expedition to Turkey, and Tuguhun and Tangut won a great victory. On the way, he captured Zhenwu Army and Li Siben, and later changed Zhenwu Army to Zhenwu County. In 920 AD, Lu Ye Po led an army to attack Tiande Military City and made Song Yao surrender. Liao was renamed Yingtianjun and Banshi. Soon, Song Yao rebelled, and Baoji sent troops again, captured Song Yao, and moved his family and Tiande German officials to the southern foot of Daqing Mountain east of Yinshan Mountain. Because it was difficult for Liao to govern the Houtao area, it had to shrink its rule eastward, and moved Fengzhou and Tiande Military Academy to Tao Qian area, and then merged into the territory of Xixia.