Despite his efforts and achievements, Zhang Liang did not participated in the governing of this new dynasty. It was rumored that he left the court for an altruistic reason.
The following information on Zhang Liang was taken from China history forum.com
Zhang Liang (張良) was crucial to Liu Bang's (劉邦) success to become emperor. He continued to be trusted by Liu Bang and the Empress Lü (呂后) after the establishment of the Han Dynasty.
When he retired from active service soon after, his counsel continued to be sought by others, including the empress when Liu Bang was considering replacing the Crown Prince (who was born by the empress) with another son born by another woman. In his retirement, Zhang Liang practiced Daoism, sought to become a mystic. He gradually reduce his food intake, believing that as he advanced in his mysticism, he would be able to survive on air alone. Concerned, the empress tried to have him force-fed, but his body rejected the sudden influx of food. It was believed he finally starved to death.
One of the reasons of this was he displayed no personal ambition. Though he was considered as one of the top three key figures in founding the dynasty, the others being the general Han Xin (韓信) and the advisor Xiao He (蕭何), he only requested the minor fief of Liu (留, present day city of Peng 彭) and the title of a marquis (侯).
He descended from a family of courtiers in the State of Han (韓). According to some historical sources, he was from a branch of the Ji (姬) clan - a royal/noble clan with many branches all over China in various states. When his State was conquered by Qin (秦), Zhang Liang was young and escaped notice as he had yet to serve in the royal court of Han. Zhang Liang came from a rich family which employed more than 300 servants, but it was said he left his own younger brother who died unburied and expended the family wealth procuring men of exceptional abilities to assassinate the king of Qin, the most famous incident being at Bo Lang Sha where the king travelled with similar carriages to confuse any enemies.
The assassin of the attempt had hurled a heavy mace weighing 200 Chinese catties from a distance, was captured and killed. Before he died though, he let slip a clue that his employer was a scion of a noble house of a vanquished state. As the courts of various states had kept careful records, investigation soon brought suspicions to Zhang Liang who had to flee and change his name.
Legend had it that he was accosted by an old man, but upon displaying proper respect repeatedly, he was given a manual of military strategies written by Tai Gong (太公兵法), and the old man was a famous strategist named Huang Shi Gong (黄石公).
Zhang Liang studied that manual for years before ever making his move.
Acquiring the Tai Gong's Strategy Essay From Huang Shigong
It is said that Zhang Liang was on the street one day, when he saw an elderly man sitting on the side of a bridge. The old man was wearing only one shoe. The curious Zhang Liang went over to ask him if he needed help. The old man (Huang Shigong) pointed at a shoe below the bridge (I can't remember if it was in the water or not.). Zhang Liang retrieved the shoe for him as an act of kindness. However, instead of thanking him, the old man gestured at the shoe and then at his bare foot. He wanted Zhang to wear the shoe for him as well.
Zhang Liang wasn't very pleased at first, but he felt that since he had already helped the poor old man, he might as well continue giving him a hand. So, he helped him wear his shoe. Satisfied, the old man told Zhang that he would be rewarded for his kindness. He told him to meet him at the bridge two days later (could be three, I can't recall clearly), and reminded him not to be late.
Two days later, Zhang Liang hurried to the bridge. The elder was already waiting for him. Zhang apologised for being late, but the old man was still very displeased. He told Zhang to meet him there again two more days later.
Afraid of being late again, Zhang went to the meeting place at dawn. To his surprise, the old man was already waiting there. The latter was extremely angry. Zhang apologized profusely, so the old man decided to give him one last chance. They were to meet again two days later.
Zhang Liang had learnt his lesson. On the day before the meeting, he went to the bridge to wait for the elder. He stood there waiting for his arrival throughout the night. Then, at around midnight, he saw a familiar figure appear. Yes, it was Huang Shigong. Zhang hurried forward to greet him. Huang was pleased to see him there already. He took out an old manuscript and handed it over to Zhang Liang.
Zhang found out that he had received a treasure when he went home. The book was the lost Tai Gong's Art of War (The Six Secret Teachings). His knowledge increased tremendously after studying the book. Eventually, with his knowledge on the art of war, Zhang Liang was able to aid Liu Bang in his conquest against Xiang Yu and the unification of China.
The Xian Yang Trap
The sight of the grand palace, riches from the Treasury, the fine horses and hounds, the beautiful palace maids and harem, tempted him to relapse into his old fondness of women and wine.
His general Fan Kuai (樊哙) remonstrated him to no avail, until Zhang Liang warned him he was going to become like the tyrannical Qin, giving rise to the idioms assisting Zhou in tyranny (助桀为虐), wise words do not sound attractive just as effective medicine taste bitter to the mouth (忠言逆耳利于行，毒药苦口利于病).
Heeding their advice, Liu Bang ordered the Treasury sealed, the palace secured and then withdrew to Ba Shang (霸上). He won support from the populace for abolishing the harsh laws of Qin, refusing to receive gifts from them and treated them kindly.
Meanwhile, Xiang Yu's advance was delayed because he was busy fighting the Qin general Zhang Han (章邯) at the Battle of JuLu (巨鹿). By the time he vanquished the enemy forces, news was received that Liu Bang had secured the HanGu Pass (函谷关).
Xiang Yu was enraged and despatched his generals, including Ying Bu (英布), to take the Pass. They broke through the Pass and advanced till XiXi (戏西), east of present day LinTong county in ShaanXi (今陕西临潼县东).
Cao WuShang (曹无伤), a general who served under and later betrayed Liu Bang, reported that Liu Bang was planning to make himself King of Guan Zhong (关中), appointing the deposed Qin ruler ZiYing as premier and keep the all the loot for himself. Xiang Yu got angrier and ordered his army to prepare for total assault on Liu Bang the following day.
It was at this time that the Left Minister of Chu (楚左尹), Xiang Bo, made a secret visit at night to Liu Bang's camp to persuade Zhang Liang to flee. Xiang Bo wanted to repay for his debt to Zhang Liang.
Zhang Liang felt it was unseemly for him to desert Liu Bang in his hour of trouble, and brought Xiang Bo to Liu Bang to warn him of the impending doom.
Liu Bang was alarmed and sought Zhang Liang's counsel.
Zhang Liang asked him,"Do you really want to turn against Xiang Yu?"
Liu Bang said,"It was an ill-conceived advice from Yu Lou (愚陋) that I accepted the suggestion to secure Han Gu Pass against other warlords in order become King of Guan Zhong."
Zhang Liang asked him again,"How do you estimate your strength against Xiang Yu?"
Liu Bang thought a long while before answering,"It was incomparable to begin with."
Zhang Liang estimated that Xiang Yu had a force of 400,000 against Liu Bang's mere 100,000, and decided eating the humble pie was the only solution.
Zhang Liang said,"Let me tell Xiang Bo that you were thought of turning against Xiang Yu."
Xiang Bo was invited into the meeting, and Liu Bang treated him respectfully as an elder brother, toasting him wine and even proposed marriage alliance.
The securing of Han Gu Pass was explained as preventing other looters from entry, not meant to defy Xiang Yu. Xiang Bo instructed Liu Bang to come personally to Xiang Yu's camp the next day to apologise.
The meeting that followed on the next day was immortalised in the Chinese phrase Hong Men Yan (鸿门宴), or Banquet at the Swan Gate.
Liu Bang's humbling submission of himself pacified Xiang Yu's anger. He further explained that ZiYing, the Treasury and Palace were all secured and awaited Xiang Yu's pleasure. In contrast to Liu Bang, Xiang Yu had Zi Ying killed, looted the treasury and burned the Palace. His conduct was a great contrast to Liu Bang.
During the banquet, Xiang Yu's general Fan Zeng (范增) felt Liu Bang was too dangerous and tried to kill him while performing a sword dance. Liu Bang's life was spared only when Xiang Bo interposed himself into the dance, using his body to shield Liu Bang.
In 206BC, Xiang Yu divided Qin's empire and enfeoffed various commanders. Liu Bang was conferred as King of Han (汉王), with territories in Ba (巴), Shu (蜀) and Han Zhong (汉中).
Zhang Liang was rewarded with a hundred taels of gold and two pecks of pearls, which he presented to Xiang Bo.
Before Liu Bang departed for his new territories, Zhang Liang advised him to destroy the road of Zhan Dao (栈道) behind him in order to allay suspicion that Liu Bang had eastward ambitions. It also prevented any enemies from pursuing from his rear.
Zhang Liang returned to the State of Han, but his master King Cheng of Han was ordered to follow Xiang Yu to the east instead of being allowed to return to Han. Xiang Yu was concerned because King Cheng of Han had fought alongside Liu Bang earlier.
Zhang Liang warned Xiang Yu of treachery from the Tian Rong (田荣), the King of Qi (齐王). This occupied Xiang Yu's attention for a northern punitive expedition, distracting him from caution against Liu Bang in the west.
Openly Repair the Gallery roads,
but Sneak through the Passage of Chencang
Xiang Yu had originally taken the precaution of stationing three vassals, Zhang Han (章邯), Sima Xin (司马欣) and Dong Yi (董翳) in various parts of the former Qin territories against Liu Bang.
As the main road had been burned, the three generals relaxed their guards. When Liu Bang sent a small workforce to restore it, they did not take note because it was thought the work would take too long to be of concern.
But the repair work was just a ruse, Liu Bang actually led his forces in secret by alternative routes and attacked the three vassals. By the time Liu Bang's general Han Xin (韩信) successfully subdued the three vassals, Xiang Yu had demoted the King of Han to a marquis, and eventually had him killed in the city of Peng (彭).
Zhang Liang escaped and joined Liu Bang, who conferred upon him the title of Marquis of Cheng Xin (成信侯). Their eastwards march was trounced by Xiang Yu at the battle of Peng.
Retreating to Xia Yi (下邑), present day An Hui (安徽砀山县), Liu Bang considered offering the territories east of Han Gu Pass to seek allies who would support his quest for dominance.
Zhang Liang advised him that King Qiong Bu of Jiu Jiang (九江王黥布), the notorious general of Chu, have disagreements with Xiang Yu. Peng Yue (彭越) and the King of Qi also oppose Xiang Yu. We should exploit them instead. Your general Han Xin is capable of taking the field by himself. Together with these three, we can defeat Xiang Yu.
Liu Bang accepted the advice. Sui He (隋何) was sent to ally with Ying Bu (英布)，and another to ally with Peng Yue. When King Bao of Wei (魏王豹) turned against Liu Bang, Han Xin was despatched to bring him down, and at the same time, seized the lands of Yan (燕), Fa (代), Qi (齐) and Zhao (赵).
Thus, Ying Bu, Peng Yue and Han Xin were instrumental in Liu Bang's final victory over Xiang Yu. But there were still more wars in between and Liu Bang was on the verge of total defeat more than once.
Yi LiQi pointed out to the examples of King Tang (汤) who after deposing the tyrannical King Jie (桀) of Xia (夏) dynasty, established the Shang (商) dynasty but at the same time confer the descendants of the Xia dynasty a fief in Qi (杞), and also the example of King Wu of Zhou (周武王) who overthrew the despotic King Zhou (纣) of Shang (商) and confered the descendants of Shang the fief of Song (宋).
Yi LiQi proposed that since the descendants of the Six States conquered by Qin had become stateless, Liu Bang should revive the Six States, conferring the scions royal seals and thus gain the backings of the former subjects and populace of the Six States. With their support, Xiang Yu's Kingdom of Chu will have no choice but to submit.
Liu Bang was very excited and ordered him to make and deliver the seals.
Shortly afterwards, before Yi LiQi could set off, Zhang Liang arrived to visit Liu Bang. Liu Bang was happily having a meal and told Zhang Liang that all his problems were solved and all that Yi LiQi had proposed.
Zhang Liang was astounded and asked who gave him the idea that would spell his own doom.
Liu Bang anxiously asked what was the problem.
Zhang Liang analysed carefully the difference between Liu Bang's current situation and the situations of King Tang of Shang and King Wu of Zhou when they "killed off" the other lords.
King Tang and King Wu had already achieved victories over their respective foes, and were in the position to bring death to King Jie and King Zhou.
King Wu had suffered physical humiliation when he submitted earlier to King Zhou of Shang, and was thus identified with Bi Gan (比干), a well loved minister of Shang. He already established his reputation.
Those Kings had already established deeds by various undertakings which reflected their merits and their trustworthiness. The populace in their own home states displayed a high degree of civility which was admired by other states.
Another critical issue was if the Six States were to be revived, then all their former lands and subjects would revert to the Six States, including many of Liu Bang's current troops and officers. There would be no place in the realms left for Liu Bang's Kingdom of Han. At the present, Xiang Yu's Kingdom of Chu was strong, and it was unlikely the revival of the Six States would elevate Liu Bang to be the hegemonist.
Upon hearing Zhang Liang's analysis, Liu Bang spat the food out of his mouth and swore at the pedant whose idea nearly finished him off for good. The newly carved royal seals were destroyed immediately.
When Liu Bang received the message, he was still besieged by Xiang Yu's forces in the city of Ying Yang. Upon reading the message, he swore out loud,"Damned it, I have been waiting for you to come and relieve the siege here and there you are dreaming about becoming a King!"
Zhang Liang and Chen Ping (陈平) discretely stepped on Liu Bang's toes and whispered to him, telling him that he was at a disadvantage and there was little he could do about Han Xin. Better to treat him favourably to win his support to avoid another fall out.
Liu Bang immediately realised his folly and continued to swear out loud,"Damned it, a real man who subdued other lords should be a real King, what's with this "namby pamby" acting that he is already the king. ..."
Zhang Liang was dispatched to Qi to present Han Xin with the royal seal and to confirm him as the real King of the State of Qi, and to ask him to deployed the army against Xiang Yu.
Xiang Yu suffered grave defeats and finally sued for peace.
Xiang Yu's Kingdom of Chu and Liu Bang's Kingdom of Han (汉) agreed on Swan Waterway (Hong Gou, 鸿沟) as the boundary dividing the entire realm between them, east to Xiang Yu, west to Liu Bang.
Xiang Yu withdrew his troops eastwards, thinking he could finally enjoy his position as hegemonist of the east.
Liu Bang was preparing to do the same until Zhang Liang and Chen Ping advised him that Liu Bang already had the submissions from various lords, and that Chu's troops and supplies were exhausted, Liu Bang should seize the opportunity to finish Xiang Yu once and for all and take over Xiang Yu's lands. If Xiang Yu was given the chance to recover, there will be no end of trouble that would follow.
Liu Bang took their advice and decided to "retire" his rival.
Upon reaching the village of Gu Ling (固陵), south of present day Tai Kang in He Nan 河南太康县南), Peng Yue and Han Xin had not arrived. Liu Bang inquired of Zhang Liang.
Zhang Liang surmised that it was because Peng Yue and Han Xin had not been granted a permanent fief. He pointed out Liu Bang may not win the war without their support. He proposed that Liu Bang grant Han Xin the lands east of Chen county (陈县) all the way to the coast, and to Peng Yue the lands north of Sui Yang (睢阳) all the way to the city of Gu (毂城). These were part of Xiang Yu's territories, and hence Han Xin and Peng Yue would have the incentive of fighting to win their own lands. Motivated by self-interest, they would be able to fight and beat Xiang Yu.
Liu Bang followed the plan, and sure enough, Han Xin and Peng Yue and other lords joined forces with Liu Bang at Gai Xia (垓下), present day south of Ling Bi in An Hui (安徽灵壁南).
At the battle of Gai Xia, Xiang Yu's army was destroyed and the war finally ended.
Establishing the Han Dynasty
Though Zhang Liang never fought in combat, Liu Bang pointed out that it was Zhang Liang's strategies and planning within the camp that determined the victories that were thousands of miles away.
Liu Bang wanted to confer Zhang Liang a fief in Qi (齐) with 30,000 families.
Zhang Liang modestly declined saying he never forgot his first meeting with Liu Bang in Liu (留) after coming out of seclusion from Xia Pi (下邳). He said he greatly appreciated the way Liu Bang trusted and employed him, and it was also fortunate that the ideas proposed to Liu Bang were effective. Zhang Liang then requested the humble holdings of Liu (留).
The remembrance of their first meeting at Liu (留) brought back nostalgic memories to Liu Bang who was very moved and agreed to Zhang Liang's request.
After conferring more than 20 followers, the rest were arguing day and night on the relative merits of the services they rendered. Some generals grouped together in twos and threes discussing among themselves, making various diagrams and markings on sandy grounds.
Many became apprehensive because according to their calculations of conferring territories according to military services, there is not enough land in the entire realms!
Emperor GaoZu (Liu Bang) again turned to Zhang Liang for advice.
Zhang Liang suggested the Emperor's next conferring should be to Yong Chi (雍齿). Everyone knew how Liu Bang personally hated Yong Chi. Once it was seen that even Yong Chi was conferred as a marquis with his own holdings, they ceased to worry and became relieved. This alleviated the tensions among the followers.
The next important decision following the unification was the choice of the location of the Imperial capital.
During a discussion by the emperor and his ministers, Liu Jing (刘敬) proposed the Guan Zhong (关中) region. Most of the ministers on the emperor's left came from Shan Dong (山东) and advocated for the ancient city of Luo Yang (洛阳), former capital of the Zhou dynasty. They reasoned that Luo Yang had Cheng Gao (成皋) to its east, Gu (殽) and Min (黾) to the west, bounded by the river Xiang Qu (乡雒), and is thus a hardy and self sufficient location.
According to "Han Su, Accounts of Zhang Liang" 《汉书·张良传》, it was Zhang Liang who advised the indecisive Liu Bang to arrived to a decision on where to establish his new capital.
On the other hand, Guan Zhong also had the strategic advantages of Gu (殽) and Han (函) to the east, the fertile lands of Long (陇) and Shu (蜀) to the west for thousands of miles. The west could act as the support to the capital, while in any event of rebellion of the feudal lords, punitive expeditions could be launched downstream of the Yellow River. Zhang Liang's conclusion was that it was the Golden City commanding thousands of miles of territories, backed by the land of great abundance. Liu Jing also agreed to the assessment.
Liu Bang set off on the very day to establish his new capital in the Guan Zhong region, in the city of Chang An (长安).
In feudalistic societies, changing of the Crown Prince was a grave matter that directly affects the stability of the political establishment. Senior ministers such as Shusun Tong (叔孙通) and Zhou Cang (周昌) protested strongly, but could not talk the Emperor round.
Empress Lü was especially fearful and tried all means to no avail. Finally, she cornered Zhang Liang for his assistance. Zhang Liang felt that it was not a matter that the Emperor could be persuaded by means of arguments.
He suggested that the Crown Prince Liu Ying humbled himself and sought four highly revered sages that the Emperor himself had sought repeatedly but never succeeded. The four sages, wizened white haired old men, were known as the Four Luminescents (四皓), agreed and accompanied the Crown Prince into the Imperial Court. When Liu Bang saw that Liu Ying had won the support of the four sages that he (Liu Bang) could not, he was led to believe that the Crown Prince had popular support and a solid political base, and hence gave up the idea of deposing Liu Ying as the Crown Prince, who eventually succeeded the throne as Emperor Hui (惠帝).
Incidentally, Liu Ying was not the warrior like his father. When his father ordered him to lead an expedition against nomad raiders in the north, he was not up to the task. Liu Ying had no military experience while the generals he was supposed to lead were veterans of his father's campaigns, being fierce warriors who needed a strong leader like his father. But Liu Ying was not a coward either. When he ascended the throne, his mother held much power but Liu Ying made a great effort to prevent his mother from harming RuYi.
Since then, Zhang Liang quitted politics, remaining at home with the excuse of being ill. He followed a strict practice of Daoism which include greatly reducing food intake. Grateful for his help, Empress Lü tried to make him eat, questioning his needless suffering in the short span of humanlife. Zhang Liang was forced to comply, but his body rejects much of the food.
Six years later, Zhang Liang passed away and was posthumously conferred as Marquis of Cheng (成侯). His march was succeeded by his son Zhang BuYi (张不疑).