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.