Regency and buildup of personality cult
Emperor Ai died suddenly in 1 BC, without heir. Taking decisive action, Grand Empress Dowager Wang seized power back from Emperor Ai's male favorite and likely lover Dong Xian (who was the commander of the armed forces by this point) and summoned Wang Mang back to the imperial government. She put him in charge of the armed forces and the government. They summoned Prince Jizi of Zhongshan (the last surviving male issue of Grand Empress Dowager Wang's husband Emperor Yuan) to the capital to succeed Emperor Ai, and he ascended the throne as Emperor Ping. Wang Mang became his regent.
Also in 1 BC, Wang, now in power, took drastic action to attack actual or perceived political enemies:
- The relations of Emperor Ai, the Fus and the Dings, were demoted and exiled back to their ancestral lands.
- Empress Dowager Zhao Feiyan, the wife of Emperor Cheng (who was friendly with the late Grand Empress Dowager Fu), and Empress Fu, the wife of Emperor Ai (and related to Grand Empress Dowager Fu) were demoted to commoner status and ordered to guard their husbands' tombs. They committed suicide in response.
- Grand Empress Dowager Fu and Empress Dowager Ding were posthumously demoted—to the titles of "the mother of Prince Gong of Dingtao" and "Consort Ding" respectively. (In 5 CE, Wang would further disinter Consorts Fu and Ding's caskets and strip their bodies of jade burial shells, and then return the bodies to Dingtao to be buried there. Their tombs were then completely flattened and surrounded with thorns.)
- Dong Xian (who had committed suicide soon after his demotion) was disinterred and reburied within a prison, and his clan was exiled.
- He Wu (何武), the former prime examiner, and his friend Gongsun Lu (公孫祿), who had opposed Wang Mang's regency, were relieved of their posts.
- Wujiang Long (毋將隆), the governor of the Nan Commandery (roughly modern Hubei), who had rejected Wang Mang's advances to serve as a political ally, was falsely accused of having falsely accused the innocent Princess Dowager Feng Yuan of Zhongshan of witchcraft in 6 CE, and he, along with the real co-conspirators against Princess Dowager Feng, were exiled.
Wang, having thus consolidated his power, began to further build up his personality cult, encouraging others to submit false prophecies in which he was mentioned as the second coming of Ji Dan, the Duke of Zhou and the regent for King Cheng of Zhou, or other great mythical personalities. He also began a regime of modifying the governmental structure to recall the governments of the Zhou Dynasty and the even more ancient Shang Dynasty. This included numerous changes to officials' titles and even to geographical locations. To prevent Emperor Ping's maternal uncles of the Wei clan from becoming powerful, he ordered that they, along with Emperor Ping's mother
Consort Wei, not be allowed to visit him in the capital.
In AD 1, after bribing the distant Yueshang Tribes (probably in modern southern Vietnam) to submit offerings of an albino pheasant (considered a rare sign of divine favor), Wang was successful in having his followers persuade Grand Empress Dowager Wang to create him the Duke of Anhan (安漢公) – even though the Han nobility system did not include dukes and no duke had ever been created in Han history up to that point—to let his title parallel that of the Duke of Zhou. Believing her nephew to be truly faithful, Grand Empress Dowager Wang further transferred more of her authority to him.
In AD 2, Wang Mang issued a list of regulations to the ally-vassal Xiongnu, which the Xiongnu chanyu Nangzhiyasi (囊知牙斯—later shortened to Zhi in response to Wang Mang's request) obeyed, but Wang Mang's tone of treating Xiongnu as a subordinate state rather than an ally offended Nangzhiyasi, which would foreshadow the eventual breakdown of relationships with the Xiongnu. Also in AD 2, Wang Mang decided to have his daughter married to Emperor Ping to further affirm his position. Initially, he started a selection process of eligible noble young ladies (after declaring, in accordance with ancient customs, that Emperor Ping would have one wife and 11 concubines). However, in an act of false modesty intended to create the opposite result, he then petitioned Grand Empress Dowager Wang that his daughter not be considered—and then started a petition drive by the people to have his daughter selected as empress. The petitioners stormed the outside of the palace, and Grand Empress Dowager Wang, overwhelmed by the display of affection for Wang Mang, ordered that Wang Mang's daughter be made empress. In 4 CE, Emperor Ping officially married her and made her empress.
Wang Mang's son Wang Yu (王宇) disagreed with his father's dictatorial regime and program to build up his personality cult, afraid that in the future the Wangs would receive a backlash when Emperor Ping was grown. He therefore formed friendships with Emperor Ping's Wei uncles, and told Consort Wei to offer assurances to Wang Mang that she would not act as Emperor Ai's mother and grandmother did, trying to become an empress dowager. Wang Mang still refused to let her visit the capital.
In AD 3, Wang Yu formed a conspiracy with his teacher Wu Zhang (吳章), his brother-in-law Lü Kuan (呂寬), and the Weis, to try to see what they could do to break Wang Mang's dictatorial hold. They decided that they would create what appeared to be supernatural incidents to make Wang Mang concerned, and then have Wu try to persuade Wang Mang to transfer power to the Weis. Wang Yu told Lü to toss a bottle of blood onto Wang Mang's mansion door to create that effect—but Lü was discovered by Wang Mang's guards. Wang Mang then arrested Wang Yu, who committed suicide, and his wife (Lü Kuan's sister) Lü Yan (呂焉) was executed. Wang Mang subsequently executed the entire Wei clan, except for Consort Wei. Wu was cut in half and then drawn and quartered. (It is not known what happened to Lü, but it would appear that there would be no way for him to escape death.)
Wang Mang took this opportunity to further wipe out potential enemies—by torturing Wang Yu and Lü's co-conspirators, arresting anyone that they mentioned, and having them either executed or forced to commit suicide. The victims of this purge included Emperor Yuan's sister Princess Jingwu (敬武長公主), Wang Mang's own uncle Wang Li, and his own cousin Wang Ren. He falsely told Grand Empress Dowager Wang, however, that they had died of illnesses. Many other officials who were not willing to follow Wang Mang were also victimized in this purge. After this, Wang Mang's hold on power became absolute. In AD 5, Wang Mang revived an ancient ceremony intended for those who have made great contributions to the state, and had himself given the nine bestowments (九錫). (The "nine bestowments" would, after Wang Mang, thereafter become a customary step for usurpers to receive before they usurped the throne.)
Around AD 5, Emperor Ping, having grown older, appeared to grow out of a heart condition from which he suffered as a child, and it became fairly plain that he resented Wang for slaughtering his uncles and not allowing his mother to visit him in Chang'an. Wang therefore resolved to murder the emperor. In the winter of 5, Wang submitted pepper wine (considered in those days to be capable of chasing away evil spirits) to the 13-year-old emperor, but had the wine spiked with poison. As the emperor was suffering the effects of the poison, Wang wrote a secret petition to the gods, in which he offered to substitute his life for Emperor Ping's, and then had the petition locked away. (Historians generally believed that Wang had two motives in doing this—one was, in case Emperor Ping recovered from the poisoning, to use this to try to absolve himself of involvement in the poisoning, and the second was to leave for posterity evidence of his faithfulness.) After a few days of suffering, Emperor Ping died.