At the end of the Western Jin Dynasty, Liu Yuan, the Hun, successfully established hanzhao (also known as Qian Zhao or Han state) and let some relatively small anti Jin forces attach to him.
After the establishment of the Western Jin Dynasty, Sima Yan (known as Emperor Wu of Jin in History) successfully reunified China.
In 220 AD, Cao Pi became emperor and established the power of Cao Wei.
In 2 ad, drought and locusts occurred in the Central Plains.
In 25 ad, Liu Xiu and his entourage decided that the time was right and decided to stand on their own as emperor. (he was known as Emperor Guangwu of the Han Dynasty in History).
In 202 BC, Liu Bang, king of the Han Dynasty, became the emperor officially, known as Emperor Gaozu of Han Dynasty in history. (the Western Han Dynasty dates from 206 BC when Liu Bang was called the king of the Han Dynasty).
After the King of Qin Ying Zheng eliminated the six countries, he successfully unified China.
After the collapse of the Western Zhou Dynasty,the princes established Yi jiu as the new emperor of Zhou.