After assembling forces and proclaiming himself emperor in the face of competitors, he was able to defeat his rivals, destroy the peasant army of the Chimei, known for their disorganization and marauding, and finally reunify China in AD 36.

He was, in particular, one rare example of a founding emperor of a dynasty who did not kill, out of jealousy or paranoia, any of the generals or officials who contributed to his victories after his rule was secure.

He was the son of Liu Qin (劉欽), magistrate (縣令 i.e., head official) of Nandun County (南頓縣), near present-day Xiangcheng, Henan.

In AD 22, with virtually the entire empire rebelling against Wang Mang's incompetent rule, Liu Yan prepared his rebellion.

Encouraged, Liu Yan made a frontal assault against Wancheng (宛城), the capital of Nanyang Commandery—and suffered a major loss.

In AD 23, they had a major victory against Xin forces, killing Zhen Fu (甄阜), the governor of Nanyang Commandery.

The Han forces were at this point in two groups—one led by Wang Feng (王鳳), Wang Chang (王常), and Liu Xiu, which, in response to the arrival of the Xin forces, withdrew to the small town of Kunyang (昆陽, in modern Ye County, Henan) and one led by Liu Yan, which was still besieging Wancheng.

When he heard about his brother's death, he quickly left his army and went back to the temporary capital Wancheng to beg forgiveness.

(According to Hou Han Shu, when Liu Xiu was younger, he visited the capital Chang'an; he became impressed with the mayor of the capital (zhijinyu, 執金吾) and, also impressed by Yin's beauty, he made the remarks: "If I were to be an official, I want to be zhijinyu; if I were to marry, I want to marry Yin Lihua".

Deng, seeing that the Gengshi Emperor lacked the ability to rule, persuaded Liu Xiu to keep his sights broad and consider eventual independence.

Ren's deputy Li Chong (李忠), Wan Xiu (萬脩) and Liu Zhi (劉植), who was powerful clan in the region, also joined him.

The combined forces gave Liu Xiu enough strength to make a direct assault against Handan, trapping and killing Wang Lang.

After Wang's death, Gengshi Emperor made Liu Xiu the Prince of Xiao and summoned him back to the capital (then moved to Chang'an).

Liu Xiu, persuaded by Geng Yan that he should be ready to set out his own course because the people were badly shaken by Gengshi Emperor and his officials' misrule, declined and claimed that the region still needed to be pacified.

In the autumn of AD 24, Liu Xiu, still ostensibly an official under Gengshi Emperor, successfully pacified some of the larger agrarian rebel groups and merged them into his own forces.

At this point, territories that Liu Xiu controlled were already impressive, compared to any other regional power in the empire broken apart by civil war—but he still carried just the title Prince of Xiao (which Gengshi Emperor had created him) and still ostensibly was controlling those territories as Gengshi Emperor's deputy, even as he was already engaging militarily against some generals (e.g. Xie Gong – 謝躬) loyal to Gengshi Emperor (During this incident, Liu Xiu succeeded to persuade Ma Wu (馬武), who was the deputy of Xie Gong, to join him.).

Emperor Guangwu, anticipating this, set up his forces to harass and tire the Chimei out, and then block them off at Yiyang (宜陽, in modern Luoyang, Henan).

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.

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.

After some initial successes, Wei's small independent regime eventually collapsed under overwhelming force and was reduced severely.

In the winter of AD 34, Shuoning's capital Luomen (落門, in modern Tianshui, Gansu) fell, and Wei Chun surrendered.

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.

[5][6] Although Emperor Guangwu had already created many of his generals and officials marquesses, in AD 37, after the conquest of the empire was largely complete, he readjusted their marches in accordance with their accomplishments.

For example, in AD 38, his official Liang Tong (梁統) submitted a petition to restore the criminal laws of late Western Han dynasty—which were far more severe.

Nevertheless, because of raids by Xiongnu, Wuhuan, and Xianbei, the northern commanderies became largely unpopulated, as the people suffered great casualties and also fled to more southerly lands.

Emperor Guangwu declined, stating that his empire was so lacking in strength at the time that he could not expend efforts to protect Xiyu kingdoms.

Later, in AD 24, while he was on his expedition north of the Yellow River, he entered a political marriage with Guo Shengtong (郭聖通), the niece of a regional warlord, Liu Yang (劉楊) the Prince of Zhending.

In AD 43, Emperor Guangwu agreed and made Liu Yang (劉陽), the oldest son of Empress Yin, crown prince instead.

He had once again commissioned Ma Yuan to go on an expedition—against the indigenous people of the Wulin Commandery (modern northwestern Hunan and eastern Guizhou), who had rebelled.