Liu Bobo was born in 381, when his father Liu Weichen was an important Xiongnu chief and a vassal of Former Qin.

It is not known whether his mother Lady Fu was Liu Weichen's wife or concubine.

He was one of Liu Weichen's younger sons.

After Former Qin collapsed in light of various rebellions after its emperor Fu Jiān's defeat at the Battle of Fei River in 383, Liu Weichen took control of what is now part of Inner Mongolia south of the Yellow River and extreme northern Shaanxi, and while he nominally submitted to both Later Qin and Western Yan as a vassal, he was actually a powerful independent ruler.

However, in 391, he sent his son Liu Zhilidi to attack Northern Wei's prince Tuoba Gui, and Tuoba Gui not only defeated Liu Zhilidi, but crossed the Yellow River to attack Liu Weichen's capital Yueba (in modern Ordos, Inner Mongolia), capturing it and forcing Liu Weichen and Liu Zhilidi to flee.

The next day, Liu Weichen was killed by his subordinates, and Liu Zhilidi was captured.

Tuoba Gui seized Liu Weichen's territory and people and slaughtered his clan.

However, Liu Bobo escaped and fled to the Xuegan tribe, whose chief Tai Xifu refused to turn him over despite Northern Wei demands.

Instead, Tai delivered Liu Bobo to the Xianbei tribal chief Mo Yigan, the Duke of Gaoping, a Later Qin vassal, and Mo Yigan not only gave Liu Bobo refuge but also married one of his daughters to Liu Bobo.

Liu Bobo, from that point on, became highly dependent on his father-in-law.

(Meanwhile, in 393, Tuoba Gui, because of Tai Xifu's refusal to deliver Liu Bobo to him, attacked Tai and slaughtered his people, although Tai himself escaped and fled to Later Qin.)

Little is known about Liu Bobo's life during the following years.

In 402, Tuoba Gui's brother Tuoba Zun, the Prince of Changshan, attacked Mo's home base of Gaoping (in modern Guyuan, Ningxia), and Mo was forced to flee to Later Qin, abandoning his own people, who were scattered about, although later Later Qin recaptured Gaoping and gave that city back to Mo.

Sometime before 407, Liu Bobo, who has become known for being handsome, ability to speak well, alertness, and intelligence, had come to the attention of Later Qin's emperor Yao Xing.

Yao Xing had been so impressed by Liu Bobo's abilities when he met Liu Bobo that he wanted to make him a major general to defend against Northern Wei.

Yao Xing's brother Yao Yong, however, spoke against it, believing Liu Bobo to be untrustworthy.

Yao Xing initially, at Yao Yong's counsel, did not give Liu Bobo a commission, but eventually was so seduced by his talent that he made him a general and the Duke of Wuyuan, giving him the responsibility of defending Shuofang (in modern Ordos as well).

In 407, after suffering a number of losses against Northern Wei, Yao Xing decides to make peace with Northern Wei.

Upon hearing this, Liu Bobo becomes angry, because his father had been killed by Northern Wei, and he plans rebellion.

He therefore forcibly seizes the horses that Yujiulü Shelun), the khan of Rouran, had recently offered to Yao Xing as a tribute, and then makes a surprise attack on his father-in-law Mo Yigan, capturing Gaoping and killing Mo, seizing his troops.

He then declares himself a descendant of Yu the Great, the founder of Xia Dynasty, and names his state Xia.

He claims the title "Heavenly Prince" (Tian Wang).

Despite Liu Bobo's stated hatred for Northern Wei, he concentrates his efforts on undermining Later Qin, continually harassing Later Qin's northern territories and draining Later Qin's resources.

He therefore does not settle in a capital city; rather, he roved about with his mobile cavalry, constantly looking for Later Qin cities to pillage.

Also in 407, Liu Bobo seeks marriage with a daughter of the Southern Liang prince Tufa Rutan, but Tufa Rutan refuses.

In anger, Liu Bobo launches a punitive raid against Southern Liang, then retreats.

Tufa Rutan gives chase and, believing that he greatly outpowers Liu Bobo, is careless in his military actions.

Liu Bobo leads him into a canyon and locks the exit with ice and wagons, then ambushes him.

The defeat is such that it was said that sixty to seventy percent of Southern Liang's famed officials and generals died in the battle.

Tufa Rutan barely escapes capture.

Yao Xing sends his general Qi Nan to launch a major attack on Liu Bobo in 408.

Liu Bobo initially withdraws to let Qi believe that he fears Qi, and Liu Bobo makes a surprise counterattack and captures Qi.

Subsequently, much of Later Qin's northern territories fall into Xia hands.

Yao Xing himself launches an attack on Liu Bobo in 409, but when he reaches Ercheng (in modern Yan'an, Shaanxi), he is nearly trapped by Liu Bobo, and escapes only after major casualties.

This defeat forces Yao Xing to cancel a mission, commanded by his general Yao Qiang, to try to save Southern Yan from being destroyed by Jin.

(Without Later Qin aid, Southern Yan will fall in 410.)

Xia and Later Qin forces have battled constantly, often inconclusively, for the past several years, but with the wars becoming much more costly to Later Qin than Xia, with Southern Liang and Western Qin no longer being willing to be Later Qin vassals as a result.

In 412, when Western Qin's prince Qifu Gangui is assassinated by his nephew Qifu Gongfu, Liu Bobo considers attacking Western Qin despite its status as an ally, but at the counsel of his advisor Wang Maide does not do so.

Liu Bobo finally resolves by 413 to build a capital—one that he wants to make absolutely impenetrable.

He commissions his cruel general Chigan Ali as the chief architect of the capital, which he names Tongwan—because, as he states, he wants to unite China and be the lord of ten thousand states.

("Tong" means "unite," while "wan" means ten thousand.)

Chigan orders that the soil used in constructing the wall be steamed, so that it will be hardened and difficult to attack, and he often tests the walls during its construction; if an iron wedge were able to insert even one inch deep into the wall, the workmen who were in charge of that section of wall would be executed, and their bodies would be stuffed into the wall.

Further, Liu Bobo himself ordered that when weapons and armors are made, that some of the metalsmiths would be executed—because his orders were, for example, that arrows should be shot at armor; if the arrows could penetrate the armor, the smiths who forged the armor would be executed, and if the arrows could not penetrate the armos, then the smiths who made the arrows would be executed.

As a result of this bloodshed, however, Tongwan becomes a highly defensible city, and the weapons and armors that he has are all of exceedingly high quality.

Also in 413, Liu Bobo believes that his family name should be changed—since his ancestors took on the Liu family name from the Han Dynasty imperial house, believing that one of their female ancestors was a Han princess, but Liu Bobo believes this to be improper.

He therefore changes his family name to Helian—intending it to mean that his might is so great that it would, alas be connected to the heavens.

He also orders the nobles to change their family name to Tiefa, intending it to mean that they are as strong as iron (tiě) and be able to attack (fá) others.