This one-hundred and seventy year span is the continuation of the division and chaos of the Eastern Chin and the Sixteen Kingdoms of the Five Barbarians now known as the Southern and Northern Dynasties as well as one-hundred and seventy years of a complex and intricate political stalemate between the north and the south. One the one hand north and south each had their own separate governments but on the other there also existed a complex military and political interplay between the two. To understand this kind of situation we should intermingle the account of the relation of war and peace between north and south with their political situation. We begin with the military situation between the Sung and the Wei: Liu Yü's replacement of Sung for Chin resulted in an old government being given a new ruling house; while the T'o-pa clan's state of Wei in the north was a power that was newly risen. Before Liu Yü's northern campaigns separating these two powers was the vast expanse of the Central Plain and the Yellow and Lo rivers serving as a buffer zone and there was no direct contact between the two. By the time Liu Yü had recovered the Yellow and Lo Rivers, the two powers were involved in a head-to-head clash. At the very beginning the House of Liu had not yet stabilized its political authority and so also the T'o-pa clan had not yet unified the north so they were both uncertain about each other, not daring to encroach upon the rights of the other to maintain a very brief peace. This continued until the T'o-pa Wei state had completely unified the north and the Southern Dynasties had reached the time of the reign of Sung Wen-ti, Liu I-feng. The northern court was vigorous and ambitious, long harboring the notion of invading the south so there was no way that this forced peace could be maintained and it was not long before an all out conflict developed. At first the focus of the conflict was the strategic stuggle for the Central Plains and the fight to control four great bases of operations, the four cities of Lo-yang, Hu-lao, Hua-t'ai and Kao-ch'iao; later the focus of the conflict shifted south to the area of Huai-pei (north-of-the-Huai) with P'eng-ch'eng as the center of the struggle; finally it shifted south once again to the Huai-nan area with Huai-yin as the center of the conflict. The general result of the war was that the north was became strong, the south weak, the north was victorious and the south defeated, as the power and influence of the north grew and expanded gradually so too did it gradually shift south to halt with a decisive battle along the river. After Sung Fei-ti coups rocked both the north and the south internally brining a temporary halt to the strategic conflict. This then in brief was the military situation between Sung and Wei. However, the Sung-Wei military operations were only the first stage in the war between north and south; the battle between Ch'i and Wei that followed is the second stage; the war between Liang and Wei the third stage. With the coming in the north of the Wei state dividing into the Chou and Ch'i states, and in the south with the passing of the revolt of Hou Ching the situation of balanced confrontation between north and south was totally destroyed and changed into a completely different situation. This situation is the aftermath of the Southern and Northern Dynasties period and it can also be said to be a transitional period between a north-south equilibrium and reunification so that after passing through this transitional period the period of the Southern and Northern Dynasties is at an end. We will begin by discussing the first stage, the course of events that marked the alternation of peace and was between the states of Sung and Wei.
Following Liu Yü's destruction of the Southern Yen state when in the year 416 he recovered the city of Lo-yang, the two banks of the Yellow River below the city had originally been within the sphere of influence of Wei. Before he had advanced to assault Lo-yang, Liu Yü had first sent out the vanguard Wang Ch'ung-te to supervise the naval units in a quick advance up the Yellow River. On the southern bank of the lower Yellow River there is a strategic military basing area by the name of Hua-t'ai (滑臺 modern Hua-hsien in Ho-nan, at this time the river flowed to the north of Hua-hsien) and guarding Hua-t'ai was the Northern Wei Yen-chou Prefect, Wei Chien, who upon hearing of the arrival of an army from the south unexpectedly abandoned the city and fled. Because of this Liu Yü was able to occupy Hua-t'ai and then go west along the river to storm the cities of Ying-yang and Lo-yang. Yü then led the navy upstream into the west but also sent a separate detachment of troops to move along the northern bank and take possession of it so that if Wei troops arrived to threaten them they would be forced to retreat by Liu Yü. After this Yü attacked and entered Kuan-chung conquering the city of Ch'ang-an, an event that greatly shook the Wei ruler, T'o-pa Ssu. His strategist Ts'ui Hao heaped praise upon the ability of Liu Yü and said that the southern troops were not to be taken lightly. Since T'o-pa Ssu was at the same time in the midst of operations in the north he sent an envoy to improve relations with Liu Yü. Later on when Liu Yü usurped the throne he also lost the lands of Kuan-chung which had been occupied by Ho-lien Po-po, but the Lo and Yellow River areas of the Central Plain were still controlled by the Southern Sung and east of the T'ung-kuan north and south faced each other across a river boundary that neither had yet transgressed.
The territory of the Northern Wei expanded day by day in the north and so too did the ambitions of T'o-pa Ssu day by day become more inflamed but because he feared Liu Yü he did not yet dare to invade the south. However, with the coming of the death of Liu Yü in 422 and the accession of Sung Wen-ti, T'o-pa Ssu recognizing that there was an opportunity here he could take advantage of, suddenly changed his attitude, arrested and imprisoned the Sung envoy and dispatched a large-scale military expedition to the south. He ordered his major officers Hsi Chin, Chou Chi, Kung-sun Piao, Shu-sun Chien and others to spread out and descend upon the south while he personally led a large force to follow up. Since the assaults were scattered so widely and the fighting so fierce the Wei army finally was able to storm the cities of Hua-t'ai, Ying-yang, Hu-lao, Lo-yang and Hsü-ch'ang. The detachment under Shu-sun Chien having fought its way into Ch'ing-chou, then saw it fortune change and was forced back by the Sung officers Wang Ch'ung-te and T'an Tao-chi. Among these the struggle for Hu-lao was the most severe as the Sung Ssu-chou Prefect, Mao Te-tsu, defended the city in a bitter battle that lasted from the 11th lunar month in the winter of 422 until the intercalary 4th month of 423 when the city was stormed by Wei forces. From beginning to end this conflict lasted for about one year and although the Wei had captured the three important bases of Hua-t'ai, Lo-yang and Hu-lao on the south bank of the Yellow River their losses amounted to one third of the men and horses, a very heavy price to pay and in addition to all of this while T'o-pa Ssu was returning with the army to P'ing-ch'eng he fell ill and died. With this diplomatic relations between north and south were broken and a source of future conflict was created.
When T'o-pa Ssu died his son T'o-pa T'ao succeeded him to become Wei T'ai-wu-ti (太武帝 Supreme Martial Emperor). T'ai-wu-ti was an extremely capable ruler during the founding period of the Northern Wei state and after ascending the throne he immediately set about concentrating all of his strength to do battle with the Jou-jan and Ho-lien Po-po and engage in expansion to the northwest, being in no hurry to move against the south. In the south Sung Wen-ti did not relish his defeat and resolved that he would recover the lost lands, therefore, he reorganized and trained the army so that in 430 he was able to mount a major counter-offensive. During the 3rd lunar month of 430 he ordered Left General Tao Yen-chih, An-pei General Wang Ch'ung-te, and the Yen-chou Prefect Chu Ling-hsiu to lead troops in an advance north. Tao Yen-chih led the navy upstream along the Huai and Si Rivers, advancing as far as Tung-chun (on the Huai) and Hsü-ch'ang (on the Si, modern Tung-p'ing in Shan-tung). Upon obtaining news of this T'o-pa T'ao rather unexpectedly automatically abandoned the four garrisons of Chin-yung (an earlier name of Lo-yang), Hua-lao, Hua-t'ai and Kao-ch'iao (in the area of Jen-p'ing-hsien in Shan-tung) in Huai-nan and the military units were all withdrawn completely to the north of the river. Incredibly the southern troops had recovered lands south of the river without any bloodshed and then divided their troops to be stationed in the four garrisions so they could not help but be pleased. Only Wang Ch'ung-te was anxious and fearful saying, "Although the Hu thralls have insufficient senses of love and justice, they have more than enough evil and cunning, now they gather the garrisions to return to the north for them must await the winter season when the river freezes over, then they will come south, so how could I not but be apprehensive?" The reason T'o-pa T'ao had withdrawn the guard was just as Ch'ung-te had thought and this was to trade land for time, assuming a passive stance until the time came when he could take the initiative, but there was also another reason and this was that the problem in Kuan-chung was not yet solved and it was difficult to fight a war a two fronts.
It was at this time that the Hsia ruler, Ho-lien Ting, in Kuan-chung concluded an agreement with the Sung to attack the Northern Wei from both sides. T'o-pa T'ao therefore asked for a plan of action from Ts'ui Hao. Hao considered the Sung-Hsia alliance to be a temporary convergence of interests that lacked any real base of mutual trust so just as the saying "even chickens cannot fly together" it was not enough to worry about. Moreover the Sung troops did not cross the river to advance but scattered along the southern bank to defend, stretched out in a line of two thousand li from east to west their military strength was dispersed. From this it is clear that the southern army had adopted a defensive posture and had no great plans. Ho-lien Ting had already become the only remaining power in the western regions and he could be easily destroyed so we should first attack the Kuan-hsi region and then as soon as it has been pacified we can then roll up the east like a mat, the area north of the Chiang and Huai will not be enough to satisfy the conquest! T'o-pa T'ao adopted this plan of Ts'ui Hao's so while forces were deployed to defend and hold the north bank of the Yellow River in personal command of a large force T'ao proceeded to the city of T'ung-wan to supervise the assault on Ho-lien Ting and finally routed him with Ting fleeing to Shang-kuei. The Wei army had now completely conquered the An-ting and P'ing-liang regions of Kuan-chung and with this complete they could now deploy their forces in an all-out counter-attack south of the Yellow River.
In the winter of 430 in the 10th lunar month the Wei Champion General An Chieh led troops in a large-scale counter-offensive to cross the river. In no time at all he had taken the two cities of Lo-yang and Hu-lao with the Sung army for the most part refusing battle and fleeing. Only Chu Hsiu-chih offered stout resistance at Hua-t'ai, but after several months when the walls had fallen and their provisions were exhausted that city also fell, so Tao Yen-chih fell back with the army to the city of P'eng-ch'eng. During the 11th lunar month of this same year the Sung Emperor oreder the Southern Expedition Major General (Chen-nan Ta Chiang-chün) T'an Tao-chi to take command of a large army as reinforcements, and he advanced the army up to the Chi River where they fought over thirty large and small engagements with the Wei forces, and were victorious in the majority of them. However, when his stores were plundered and burned by Shu-sun Chien's light cavalry in a surprise raid Tao-chi had to other choice but was forced to withdraw. The Wei forces moved quickly behind them to catch up so in the night Tao-chi sent out men to shout grain measures while weighing sand making Wei spys think that they still had provisions. The pursuit stopped and Tao-chi was able to return with the entire army. The outcome of all this was that all of the formerly lost lands south of the Yellow River that had been recovered had been lost yet again within the space of a year.
On the Northern Wei side during the two years of 430 and 431 they had taken Kuan-chung in the west and Lo-yang, the Yellow River valley and the Yen and Ch'ing regions in Shan-tung to the south in a victory of singularly decisive proportions. In 431 in the capital of P'ing-ch'eng T'o-pa T'ao held special celebrations and performed rites, offering sacrifices to inform the Imperial ancestors, rewarded officials and granted to the warriors of the battle a demobilization of ten years. At this time the Northern Wei did not yet have the intent to destroy the Sung so in the 6th lunar month of 431 the Shih-lang (Gentleman-in-Attendance) Chou Shao was sent to the Sung court in hopes of bettering relations and also to request a marriage between the two houses. In the wake of their great defeat, the Sung had suffered severe losses and also desired a respite so Sung Wen-ti lost no time in replying and the Sung-Wei conflict came to a brief halt.
T'an Tao-chi was a famous general of the Southern Court who had participated in every northern campaign and was the only one who had won more battles than he had lost and whose losses had been the least and for that he was feared by the northern armies. Tao-chi already had to his credit his successful withdrawal from Shan-tung and also had put down Hsieh Hui's threat to internal stability (a Sung revolt discussed later in the next section) who after this became Minister of Works and Chiang-chou Prefect, a man of great authority that even Sung Wen-ti envied. In 436 Sung Wen-ti became critically ill and his younger brother I-k'ang, the Minister Over the Masses and King of P'eng-ch'eng took charge of government affairs. Thinking that Wen-ti would die soon and that Tao-chi would be unable to regain dominance at the court, I-k'ang forged and Imperial edict charging Tao-chi with plotting a revolt and so he was arrested and put to death. When Tao-chi's time had come and he was removing his turban (?) he said, "Thus you would destroy your Great Wall!" (NOTE: He implies that the Sung is destroying their strongest defense.) Also executed were Tao-chi's two military consultants, Hsüeh T'ung and Kao Chin, men of such courage and strength that the people of the time compared them to Kuan Yü and Chang Fei, two heroes immortalized in the book Romance of the Three Kingdoms. When the men of Wei heard of T'an Tao-chi's death they congratulated themselves saying, "With Tao-chi dead the sons of Wu are not worth fearing again!"
After the battles of 431 the Wei rulers for many years managed affairs in the north. In 436 they eliminated the Northern Yen; in 439 they eliminated the Northern Liang and unified the north; in 444 they struck at the Jou-jan; in 445 they subdued the T'u-yu-hun and conquered Shan-shan. Day by day the territory of the Northern Wei grew greater, and day by day its fame and influence grew with it. By 445 T'o-pa T'ao had achieved broad stability in the north and renewed his interest in planning an invasion of the Sung. He sent out the populace of Chi-chou to construct a pontoon-bridge at the Kao-ch'iao ford and moved troops to the south. The Sung moved the populations of the two districts of Ch'ing-chou and Hsü-chou in order to evade this incursion. Then in 446 the Wei selected 20,000 cavalry from six provinces and sent them out in separate columns to raid the south and harass the lands to the north of the Huai and Si Rivers. T'o-pa T'ao also sent a letter to the Sung court using as a pretext the decision of the Southern Court to set up provinces and commanderies using northern place names and demanded an explanation of why this was being done. At this point Sung Wen-ti assembled his ministers to discuss both offensive and defensive plans and the Palace Deputy of the Censorate (Yü-shih Chung-ch'eng) Ho Ch'eng-t'ien outlined four strategems: one, "move the distnt to the nearest convenient spot" (i yuan, chiu chin) to make the population of the border regions fill the hinterlands of the south; two, "increase construction of fortifications" to consolidate the national defenses; three, "to gather carts and cattle" in order to make a record of provisions and weapons; four, "to count population and levy weapons" in order to put armaments in order. It was commonly felt in the south that the national potential had not yet been realized and that it would be difficult to resist the north so they first planend for their own defense. While this was going on there was a revolt in Lin-i on the southern borders and by the time the revolt was stabilized Sung Wen-ti had gradually adopted a policy of active defense with regard to the Northern Court. In 448 he used Liu Chün King of Wu-ling as the An-pei General and Hsü-chou Prefect to defend P'eng-ch'eng, and in 449 appointed Liu Tan King of Kuang-ling as the Yung-chou Prefect with a garrison at Hsiang-yang to stabilize two important garrisons in the east and west and simultaneously convened his ministers to discuss plans for aggressive action. When the Wei ruler heard that Sung was discussing the idea of invading the north he took the initiative and in 450 using a large hunt in Liang-chüan as cover, T'o-pa T'ao at the head of 100,000 infantry and cavalry swept into the south like the wind. The Sung Nan-tun Grand Administrator Cheng K'un and the Ying-chüan Grand Administrator Cheng Tao-yin both fled, abandoning their cities as the Wei troops advanced to encircle Hsüan-hu. Hsüan-hu, now modern Ju-nan-hsien in Ho-nan, was an important garrison on the upper reaches of the Huai River in the southern part of Ho-nan. The Sung military consultant Ch'en Hsien defended it vigorously and after over forty days of bitter fighting it still had not fallen so during the 4th lunar month of 450 tragically heavy losses, both dead and wounded, compelled the Wei ruler to withdraw his troops and return north. As the Wei formations returned to the north the Sung P'eng-ch'eng Grand Administrator Wang Hsüan-mo and the Tan-yang Metropolitan Prefect (Yin) Hsu Chan-chih both encouraged Sung Wen-ti to take advantage of the situation to mount a counter-attack. It was during the 7th lunar month of the same year that he then ordered the Ning-shuo General Wang Hsuan-mo, the Colonel of the Infantry Shen Ch'ing-chih and the Garrison Military Consultant (Chen-cnün ts'an-chün) Shen T'an to oversee the entry of a naval force into the Yellow River. The Ch'ing-chou and Chi-chou Prefect Hsiao Pin, the Commander of the Left Guard of the Imperial Heir (T'ai-tse Tso-wei Shuai) Tsang Chih and the Hsiao-chi General Wang Fang-hui to supervise a force of infantry and cavalry as the vanguard. In addition, Liu Chun King of Wu-ling and Prefect of Hsü-chou and Yen-chou was sent as an eastern column to proceed to Hua-t'ai, Liu Shuo King of Nan-p'ing and Yu-chou Prefect was to proceed up the middle toward Hsü-ch'ang and Li Tan the Yung-chou Prefect went with a western column to T'ung-kuan, and the three columns also had a backup composed of Liu I-kung King of Chiang-hsia and Grand Commandant and his garrison in P'eng-ch'eng who also acted as the overall commander of the armies. The militia of the six provinces north of the Yangtze were called up, each family with three adult males sending one and those with five sending two, initiating a large-scale counter-offensive. The Sung vanguard proceeded directly to Kao-ch'iao which fell without a fight when the Wei Chi-chou Prefect Wang Mai-te and the Ch'ing-chou Prefect Chang Huai-chih both abandoned the city and fled. Wang Hsuan-mo led his troops forward to besiege Hua-t'ai. While this was happeneing the central column under Liu Shuo stormed Ch'ang-she and advanced to threaten Hu-lao. The western column under Liu Tan, who was directing Liu Yuan-ching and Hsüeh An-tu, passed by Hsiung-erh Shan to take Shan-ch'eng and advance to put pressure on T'ung-kuan. Among these battles the focus was on the struggle for Hua-t'ai. Wang Hsuan-mo assaulted Hua-t'ai for several months to no avail while the killed and wounded among his forces numbered greatly. During the 9th lunar mont of this year the Wei ruler suddenly in personal command of a large force reputed to be some 100,000 strong, the sound of whose drums shook the heavens and whose power was like the welling tide. Wang Hsuan-mo fell back from Hua-ch'eng to defend Kao-ch'iang but was unable to maintain its defense and so abandoned it also. The armies of the vanguard under Hsiao Pin all fell back to defend Li-ch'eng while those under the King of Wu-ling and the King of Chiang-hsia fell back on P'eng-ch'eng. When the central column attacking Hu-lao and the western column that had taken Shan-ch'eng heard of the defeat and retreat from Hua-ch'eng and Kao-ch'iang and that a large Wei army was descending on the south then they also split up and withdrew. The two Kings of Wu-ling and Chiang-hsia had closed the city gates and defended it firmly so when T'o-pa T'ao saw that it would be difficult to attack P'eng-ch'eng he bypassed the city to advance and take Hsü-i. However, Hua-i also did not fall to the assault because of the large stores accumulated in the city while he personally led an army by long, quick marches straight to Kua-pu on the north bank of the Yangtze (Chiang-tu-hsien in Chiang-su) announcing his desire to cross the river to destroy the Sung. This threw the city of Chien-k'ang into turmoil with the common folk all packing their belongings to flee the city. The Sung army spread out along the south bank of the Yangtze in defense, deploying boats and warships the 700 li from Ts'ai-shih to Chi-yang (now Chiang-yin). Sung Wen-ti ascended the Shih-t'ou Ch'eng and gazing to the north sighed, "If T'an Tao-chi were here, how could the horses of the Hu be allowed to reach this place!" The emperor had no choice but to send envoys to seek and end to the hostilities with Wei. When the soldiers of Wei had come south this time, it was with the force of a violent storm with wild winds and driving rains that travels a thousand li in a single surge. When they reached Kua-pu they did not control all of the cities they had bypassed, their advance blocked by the Yangtze, and they were anxious that they would be unable to cross the river and even if they could then the rear-area provisions could not be transported across. In addition, the two strong towns of P'eng-ch'eng and Hsü-i had still not fallen and threatened their rear. The men of the north were also not used to conditions in the south and many had fallen ill, so for this and a multitude of other reasons the Wei troops could not maintain their positions for long. In the spring of 451 T'o-pa T'ao burned his encampments, slaughtered and plundered with reckless abandon and then left howling. In long, fast marched T'ao retreated straight from Kua-pu to P'ing-ch'eng while the towns and garrisons of the Huai River that had been taken were for the most part abandoned. In this campaign the peasants of the Huai River valley and central Ho-nan area suffered enormously and in the areas that the armies had passed through the rural communities were ruined and deserted. Those who had been either made prisoner or killed, both young and old, male and female, could not be calculated for only those taken captive to P'eng-ch'eng numbered over 50,000 families of Sung. History records that north and south of the Huai "when the swallows returned in the spring they nested in the woods" (the implication here that there were no houses for them to build their nests on which is what they would normally have done), and from this we can imagine the extent of the tragedy. Although the Wei armies had been victorious, the casualties among the men and horses were not made good, moreover, the losses were not indemnified and so after the troops withdrew back into the north many of their fellow countrymen were angry and indignant so it was not long before a coup rocked the country.
In the second year after he had returned north, T'o-pa T'ao was unexpectedly killed by his favorite minister Tsung Ai. Ai set up T'o-pa Yu, King of Nan-an, as the emperor while he monopolized the government as Ta Chiang-shün and Ta Tu-tu, killing those who dared to disagree with him, throwing the state into such an upheaval that history records the it as the "Disaster of Tsung Ai." When Sung Wen-ti obtained news of this, he considerd it another opportunity to exploit and planned to launch another northern campaign in order to avenge his previous defeat, but the court ministers all objected on the grounds that the Huai and Si River regions had not yet recovered from their recent devastation, and their peoples should not be so easily roused but Wen-ti would not listen to them. Thereupon in the year 452 he ordered Fu-chün General Hsiao Ssu-hua and Chi-chou Prefect Chang Yung to lead an army to again attack Kao-ch'iao; the Ssu-chou Prefect Lu Shuang and the Ying-chuan Grand Administrator Lu Hsiu were to attack Lo-yang again; the Yung-chou Prefect Tsang Chih and the Kuan-chu Ssu-ma Liu Yuan-ching and the Rear Army Military Consultant (Hou-chün Ts'an-chün) Hsüeh An-tu were to attack T'ung-kuan again; and once again they were to advance in three columns. Chang Yung besieged Kao-ch'iao which held out for a long time until one day the soldiers of Wei issued out of tunnels to attack the Sung camp by surprise while the Sung troops milled around startled and confused. The Wei troops took advantage of the situation to suddenly break through the encirclement and counter-attack with Chang Yung contrary to all expections suffering a major defeat and retreated. The greatest difficulties were faced by the Sung army in the Ch'ing, Hsü, Yen and Yu area (western Shan-tung, eastern Ho-nan and northern Chiang-su) where the lands were deserted and desolate leaving no provisions for the troops. Hsiao Ssu-hua had no alternative but to lead all of his forces back to Li-ch'eng. In the center Lu Shuang stormed Chang-she, routing a Wei army at Ta-suo to advance and threaten Hu-lao. The western force led by Liu Yuan-ching advanced to occupoy Hung-kuan (Ling-pao in Ho-nan) but upon hearing of the rout of the main force of the eastern column, both the western and central forces withdrew. The outcome still was a complete defeat and the circumsatnces were very similar to the campaign of 450 but differed in that the Northern Wei side was in the midst of the cunfusion surrounding Tsung Ai so there was no chance to take adavantage of the circumstances to counter-attack. From beginning to end these three years of warfare illustrate that the power of the Southern Court could not extend its reach to the Northern Court. After the defeat of 452 the resources of the Southern regime were even further reduced and following the outbreak of a series of internal disturbances the Sung government went into decline. The Northern Wei King of Nan-an tried without success to plot the removal of Tsung Ai who then had him killed. With this a Yü-lin Lang-chung (Forest of Plumes Gentleman-of-the-Palace) named Liu Ni who along with other seized and killed Tsung Ai setting up the grandson of T'o-pa T'ao, T'o-pa Chün, who became Wen-ch'eng-ti of the Northern Wei.
In 453 the second year after the Sung had lost an army at Kao-ch'iao, Shao the Imperial Heir instigated a coup killing Wen-ti, but Liu Chün King of Wu-ling put down the uprising killing Shao and then he ascended the throne to become the Sung ruler Hsiao-wu-ti. During the nine years of his reign Hsiao-wu-ti was beset by internal revolts and had no time for campaigning in the north. In the north as a youth Wen-ch'eng-ti had a regency that engaged in nourishing the people so they too did not yet campaign against the south. Although both sides could not avoid small skirmishes along the north-south border during this period there were no major engagements to make this a period of relative order and peace. When the southern ruler Hsiao-wu-ti did in the year 464 Imperial Heir Yeh ascended the throne but his misrule was such that he was killed by his aides. In the following year Huo King of Hsiang-tun ascended the throne to become Sung Ming-ti. In the same year in the north Wei Wen-ch'eng-ti died and Imperial Heir Hun ascended the throne as Wei Hsien-wen-ti.
During the era of Sung Ming-ti and Wei Hsien-wen-ti the war between the north and the south resumed. The origins of the wars are found in the internal revolt that triggered foreign invasion. In 466 Liu Tz'u-hsün King of Chin-an was declared emperor in Hsün-yang and in every corner the provincial garrisons were numerous and disorderly in their advocacy of Tz'u-hsün while the Sung Hsü-chou Prefect Hsüeh An-tu mobilized troops in his support. An-tu was a great general of the Southern Court who had repeatedly rendered distinguished military service and presently maintained a large force stationed to defend P'eng-ch'eng. Ever since the four garrisons on the Central Plain had been lost to the enemy and the loss of an army in 451 the field of battle had shifted south and P'eng-ch'eng had become a strategic focus on the northern border. It was not long before Tz'u-hsün was defeated and the disturbance at Hsün-yang quelled while Hsüeh An-tu also returned to his allegiance to the throne and negotiated his surrender. In order to put down any possible reaction Ming-ti specially sent the Chen-chün General Chang Yung and the Chung Ling-chün (Palace Intendant of the Army) Shen Hsiu-chih in command of 50,000 armored troops to march into Chiang-pei to accept the surrender. This made An-tu very suspicious and frightened so he sent envoys to request surrender to the Northern Wei at the same time sending his son as a hostage. At the same moment the Ju-nan Grand Administrator Ch'ang Chen-ch'i was also surrendering Hsüan-hi to the Wei. This was good news for the Wei which then sent two columns of troops, the Chen-tung Great General () Wei Yuan led a force east to reinforce Hsüeh An-tu and take control of P'eng-ch'eng; Chen-hsi Great General and Duke of Hsi-ho T'o-pa Shih led a force west to reinforce Ch'eng Chen-ch'i and take possession of Hsüan-hu. Wei Yuan led his troops in long, fast marches south and reached P'eng-ch'eng in 466 with An-tu coming out to greet him, and so P'eng-ch'eng was occupied by the men of Wei. At the same time T'o-pa Shih had also occupied Shang-ts'ai and Hsüan-hu. The people of the seven commanderies of Huai-hsi all dreaded the men of Wei and in droves the disaffected famlies fled south. Chang Yung and Shen Hsiu-chih marched their troops to P'eng-ch'eng but were intercepted and attacked by Hsüeh An-tu and Wei Yuan, withdrawing after a major defeat. In the midst of a sudden snowstorm there were over ten-thousand men killed or frozen to death with the corpses littering the route for sixty li, abandoning countless military supplies, Chang Yung and Shen Hsiu-chih were only able to escape with their lives. With this the lands of the three provinces of Sung Huai-pei (Hsü, Yen and Chi) and Yu province of Huai-hsi were all lost to the enemy.
As soon as Wei had possession of Sung Hsü-chou and Chi-chou in 467 the P'ing-tung "Quells the East" General Chang Sun-lu and the Cheng-nan Ta Chiang-chün Mu-jung Pai-yao were sent east to attack Ch'ing-chou. Within the space of ten days they had stormed four cities one after the other. The Ch'ing-chou Prefect Shen Wen-hsiu stoutly defended Tung-yang (I-tu in Shan-tung) for two years but with the coming of 469 the city began to fall. When it did then all of Ch'ing-chou was in the possession of the Northern Wei state. T'o-pa Pai-yao was appointed the Wei Ch'ing-chou Prefect and Inspector-General of the Military Affairs of the Ch'ing-chou, Ch'i-chou and Eastern Hsü-chou. At the same time a portion of the peasantry of Ch'ing-chou and Ch'i-chou were moved to the P'ing-ch'eng area and the P'ing-ch'i commandery was established for them to live in. at the time of the Ch'ing-chou attack the Wei "Stabilizes the East" Great General Wei Yuan continued his operations in Huai-pei. During the 8th lunar month of 467 Sung Ming-ti once again Shen Hsiu-chih to attack P'eng-ch'eng and once again he was defeated by the Wei army. The important cities of Hsia-p'ei, Su-yü and Huai-ying to the southeast of P'eng-ch'eng were all occupied by the Northern Wei. They also accumulated provisions and trained troops in P'eng-ch'eng indicating that they planned a long occupation. This strategic position that had defended the south against the north suddenly changed to become a base of operations for a northern invasion of the south. This next great battle for the Huai River valley began in 466 and lasted for three full years up to 469. The outcome was that the Wei obtained all of the lands of Huai-pei, Ch'ing-chou, Hsü-chou, Yen-chou and Chi-chou and also the strategic Huai-hsi towns of Nan-liang, Chen, Ju and Ts'ai while after this the Huai River became the Sung boundary, still holding and defending Huai-nan with a line of defense that extended from Huai-yin in the east up to Shou-yang in the west. The Prancing Cavalry General () Hsiao Tao-ch'eng (蕭道成) was also made the south Yen-chou Prefect with a garrison at Kuang-ling. And thereafter north of the Yangtze, Kuang-ling became the second line of defense against the north. The north-south struggle had therefore moved from the Yellow River valley to the lands between the Yangtze and the Huai. With regard to the rise and fall of the power of the north and the south, the battles of the last five years of the 460s formed a campaign of epoch-making proportions. After this the Sung state lacked the power and the means to counter-attack while the Northern Wei became complacent so during the 11th lunar month in the winter of 469 Wei sent envoys to the Sung court to mend relations and speak of peace, thus the was between Sung and Wei once again came to a halt.
In 471 Hsien-wen-ti of the Northern Court abdicated in favor of his son, T'o-pa Hung , to become Wei Hsiao-wen-ti. In the next year Ming-ti of the Sung passed away and the Imperial Heir Liu Yü ascended to the throne and again rebellions broke out in the south. Five years of confusion followed that finally led to the usurpation by Hsiao Tao-ch'eng and led to the situation of the Ch'i-Wei confrontation. During these five years envoys travelled back and forth between north and south maintaining a fragile peace.
Within the general scheme of the fifty-nine years of confrontation between the Sung and the Wei presented above, the course of the conflict between the two sides can be divided into three phases. The first phase is the strategic battle for the southern bank of the Yellow River fought during the period from the death of Sung Wu-ti to the early part of Sung Wen-ti's reign, the result of which was that the south lost its line of defense along the river - the four important cities of Kao-ch'iao, Hua-t'ai, Hu-lao and Lo-yang. In the military sphere the Sung were forced to assume a passive role, able only to react. The second phase if the dramatic battle of the latter part of the Yuan-chia period (414-454). These campaigns are a continuation of the preceeding ones because the Sung planned to take back the four Ho-nan garrisons and recover their lost lands. However, this led to the Wei army's rapid descent upon the south so that "Fu-li's horse came to (Kua)-pu" (NOTE: Fu-li is T'o-pa T'ao's childhood name.) The result was great distress among the peasants of the Central Plain dealing a brutal blow to the capacity of the Southern Court with it completely losing the ability to counter-attack. The third phase is the battle for the Huai River valley that was triggered by the Hsüeh An-tu affair during the T'ai-shi period (465-471) of Sung Ming-ti. In this conflict the Sung found themselves in a position of only being able to respond to events and the result was that the south completely lost the lands of Huai-hsi, Huai-pei and Ch'ing-chou, that the Huai River had become the new border between north and south, and then finally the south was pressured into settling its grievances with the north to bring a stop to the conflict between Wei and Sung.
In summary, in this half century of conflict the Sung state of the House of Liu was the loser and the two most important reasons for their defeat are: one, the actual strengths of the north and south differed by a wide margin; two, the southern administration was submerged in internecine struggles and endless internal revolts. Below we will discuss separately the political situation in both the north and the south.