Gradual victories over other regional powers
Chimei was the largest of the enemy forces that Emperor Guangwu had to deal with in his campaign to reunify the empire under the rule of his Eastern Han dynasty, but there were a number of regional powers that he had to deal with. These included:
Liu Yong (劉永), also claiming to be the proper emperor of Han, based on his lineage—as the son of Liu Li (劉立), the Prince of Liang under the reigns of Emperor Cheng, Emperor Ai, and Emperor Ping who had been forced by Wang Mang to commit suicide; he controlled the modern eastern Henan and northern Jiangsu region.
Peng Chong, who had been by this point aggravated by Emperor Guangwu's official Zhu Fu (朱浮) into rebellion (in a rare case of a succession of wrong decisions by Emperor Guangwu—mistakes that he learned from and would not repeat); he claimed the title of the Prince of Yan and controlled the modern Beijing region.
Zhang Bu (張步), nominally the Prince of Qi under Liu Yong, but who independently controlled the modern Shandong region.
Wei Xiao (隗囂), nominally the commander of the Xizhou (西州) region paying allegiance to Emperor Guangwu, but who independently controlled the modern eastern Gansu region, east of the Yellow River.
Dou Rong (竇融), nominally the governor of Liang Province (涼州) paying allegiance to Emperor Guangwu, but who independently controlled the modern western Gansu and northern Qinghai region, west of the Yellow River.
Lu Fang (盧芳), who also claimed the name Liu Wenbo (劉文伯) and claimed to be a descendant of Emperor Wu and the proper Han emperor. He, supported by Xiongnu's Chanyu Yu (輿), controlled the modern central and western Inner Mongolia region. Some Russian archaeologists have identified a Han-era Chinese-style palace unearthed near Abakan (in Southern Siberia) in 1941–45 as Lu Fang's residence after he had left China for the lands of the Xiongnu.
Gongsun Shu, who proclaimed himself emperor of Chengjia, who controlled the Yi Province, modern Sichuan, Chongqing and parts of Shaanxi, Guizhou, and Yunnan.
Of these powers, Gongsun Shu's Chengjia was wealthy and powerful, but Gongsun was content to maintain his regional empire and not carry out any military expeditions outside his empire. Instead, he sat by as Emperor Guangwu carried out his unification campaign. Emperor Guangwu, hesitant to carry out annihilation campaigns, largely preferred first trying to persuade the regional warlords to submit to him. Wei and Dou did in AD 29, and as they were assisting Eastern Han forces to the north of Chengjia, Gongsun was further discouraged from trying to expand his empire.
Also in AD 29, Liu Yong's son and heir Liu Yu (劉紆) was defeated by Eastern Han forces and killed. Also in AD 29, Peng's slaves assassinated him, leading to a collapse of his regime. Zhang, seeing the futility of resistance, surrendered and was created a marquess. By AD 30, all of eastern China was under Emperor Guangwu's rule.
Wei, seeing that Eastern Han was gradually unifying the empire, inexplicably began considering independence. He tried to persuade Dou to enter into an alliance with him to resist Eastern Han; Dou refused. When Eastern Han started considering conquering Chengjia, Wei, apprehensive of the implications of Chengjia's fall, tried to persuade Emperor Guangwu not to carry out a campaign against Chengjia, and later refused to lead his forces south against Chengjia.
Emperor Guangwu, who in any case preferred peaceful resolution, repeatedly wrote both Wei and Gongsun with humble terms, trying to get them to submit to him, promising them titles and honors. Wei continued to nominally submit but act as an independent power, while Gongsun refused outright—but continued to be indecisive and took no actions while Eastern Han's rule was being confirmed throughout the land.
Realizing that neither Wei nor Gongsun would voluntarily submit, Emperor Guangwu started a campaign against Wei in the summer of AD 30—assisted by Wei's friend Ma Yuan, who had served as Wei's liaison officer to Emperor Guangwu and had tried in vain to persuade him not to take the course of independence. In response, Wei formally submitted to Gongsun and accepted a princely title—Prince of Shuoning—from him, and also tried to persuade Dou to join him. Dou refused, and attacked Wei in coordination with Emperor Guangwu's forces. After some initial successes, Wei's small independent regime eventually collapsed under overwhelming force and was reduced severely. In AD 33, Wei died and was succeeded by his son Wei Chun (隗純). In the winter of AD 34, Shuoning's capital Luomen (落門, in modern Tianshui, Gansu) fell, and Wei Chun surrendered.
Emperor Guangwu then turned his attention to Chengjia. He commissioned his generals Wu Han, Cen Peng (岑彭), Lai She (來歙), and Gai Yan (蓋延) to go on a two-pronged attack on Chengjia—Wu and Cen leading an army and a navy up the Yangtze river from modern Hubei, while Lai and Gai led an army south from modern Shaanxi. Instead of fighting the Eastern Han expedition on the battlefield, Gongsun tried to repel them by assassinating their generals—and he was initially successful, assassinating Cen and Lai and temporarily causing the Eastern Han forces to halt. However, Eastern Han forces regrouped, and in 36 they had Gongsun surrounded in his capital Chengdu (成都, modern Chengdu, Sichuan). However, initial attempts to siege the city was unsuccessful, and Wu, then in command of the expeditory force, considered withdrawing. Persuaded by his lieutenant Zhang Kan (張堪) that Gongsun was in desperate straits, however, Wu tricked Gongsun into believing that the Eastern Han forces were collapsing from fatigue, drawing him out of the city and engaging in battle. Gongsun was mortally wounded in battle, and Chengdu surrendered in the winter of AD 36. Liu's general Wu Han then killed more than 10,000 people.
After Chengjia's fall, Dou turned over the lands under his control to Emperor Guangwu in AD 36, and was made prime controller. Lu, after initially submitting to Emperor Guangwu and made the Prince of Dai (as Emperor Guangwu maintained the fiction that Lu was actually from imperial lineage), eventually rebelled again, but, unable to succeed, eventually fled to Xiongnu in AD 42. The empire was entirely under Emperor Guangwu's rule. During the wartime, Liu's general Geng Yan massacred 300 cities.
