Editing Northern Wei (section)

=== War with Liu Song ===
[[File:Tomb Terracotta Group of Figurines, Northern Wei (tomb of Sima Jinlong).jpg|thumb|upright=2|Army of Northern Wei terracotta soldiers in [[Xianbei]] uniform, tomb of [[Sima Jinlong]], 484 CE.<ref>{{cite book |last1=Dien |first1=Albert E. |title=Six Dynasties Civilization |date=1 January 2007 |publisher=Yale University Press |isbn=978-0-300-07404-8 |url=https://books.google.com/books?id=0zp6iMZoqt0C&pg=PA223 |language=en}}</ref>]]
War between Northern Wei and Han-ruled [[Liu Song]] dynasty broke out while the former had not yet unified northern China. [[Emperor Wu of Song]] while still a Jin dynasty general, had conquered both [[Southern Yan]] in 410 and [[Later Qin]] in 417, pushing Jin frontiers further north into Wei territories. He then usurped the Jin throne and created the Song dynasty. After hearing the death of the Song emperor Wu in 422, Wei's emperor [[Emperor Mingyuan of Northern Wei|Mingyuan]] broke off relations with Song and sent troops to invade its southern neighbor. His plan is to seize three major cities south of the Yellow River: Luoyang, Hulao, and Huatai. Sizhou (司州, central Henan) and Yanzhou (兗州, modern western Shandong) and most cities in Song's Qing Province (青州, modern central and eastern Shandong) fell to the Wei army. The Liu Song general [[Tan Daoji]] commanded an army to try to save those cities and were able to hold Dongyang (東陽, in modern Qingzhou, Shandong), the capital of Qingzhou province. Northern Wei troops were eventually forced to withdraw after food supplies ran out. Wei forces also stalled in their siege of Hulao, defended by the capable Liu Song general Mao Dezu (毛德祖), but were meanwhile able to capture Luoyang and Xuchang (許昌, in modern Xuchang, Henan) in spring 423, cutting off the path of any Liu Song relief force for Hulao. In summer 423, Hulao fell. The campaign then ceased, with Northern Wei now in control of much of modern Henan and western Shandong.

[[File:Northern Wei warrior, tomb mural, Datong.jpg|thumb|left|Northern Wei warrior, tomb mural, Datong]]
[[Emperor Wen of Song]] continued the northern campaigns of his father. In 430, under the able general Dao Yanzhi, Liu Song recovered the four cities of Luoyang, Hulao, Huatai and Qiao'ao south of the Yellow River. However, the emperor's unwillingness to advance past this line caused the destruction of the empire's ally, [[Tiefu|Xia]], by the Wei. The emperor was to repeat this mistake as several northern states such as [[Northern Yan]] who had offered to ally with Liu Song against Wei were declined, eventually leading to Wei's unification of the North in 439.

In 450, Emperor Wen attempted to destroy the Northern Wei by himself and launched a massive invasion. Although initially successful, the campaign turned into a disaster. The Wei lured the Liu Song to cross the Yellow River, and then flanked them, destroying the Eastern army.

As the Liu Song armies retreated, [[Emperor Taiwu of Northern Wei|Emperor Taiwu]] ordered his troop to move south. The provinces south of the Yellow River were devastated by the Wei army. Only Huatai, a fortified city, held out against the Wei. Wei troops retreated in January 451, however, the economic damage to the Song was immense. Emperor Wen made another attempt to conquer Northern Wei in 452, but failed again. On returning to the capital, he was assassinated by the heir apparent, Liu Shao.

In 466, [[Liu Zixun]] waged an unsuccessful civil war against the Emperor Ming of Liu Song. The governors of Xu Province (徐州) and Yan Province (兗州, modern western Shandong), who earlier pleaded allegiance to Liu Zixun, in fear of reprisal from the Liu Song emperor Emperor Ming, surrendered these territories to rival Northern Wei. Northern Wei forces quickly took up defense position against the attacking forces sent by Emperor Ming. With Liu Song forces unable to siege [[Pengcheng]] effectively, they were forced to withdraw in spring 467, making these populous provinces lost to the Northern Wei.