The end of the might Han Dynasty was from 189 to 220 A.D. (about the time of its last ruler, the Emperor Xian). The dynasty was about to fall apart as there were so many factions fighting for the throne. Also, internal struggle amongst the family led to the destruction of the dynasty. These factions composed of warlords and different nobles and even officials from the imperial court. Cao Cao, one of the warlords then, began to unify the empire, under the rule of Emperor Xian. Later he escorted Emperor Xian to his base back in Xu and a new capital was established there.
Cao Cao began to rule the empire, with Emperor Xian at the throne. But his attempt to unify the Han Empire was foiled when two warlords leading the southern forces met with the Han army at the Battle of Red Cliffs.
The Battle of Red Cliffs was fought in the winter of 208/209 A.D. between the northern forces of the warlord Cao Cao whose soldiers were more superior in number, against the allied forces of warlord Sun Quan and warlord Liu Bei who united their southern forces. The Han army was defeated in the battle and Cao Cao was forced to retreat to his home base.
The Han Dynasty formally ended in 220 A.D. when the son of Cao Cao, named Cao Pi forces the Emperor Xian from his throne. When Cao Pi assumed the throne for himself, he became the emperor of Cao Wei, a new state. A year after this, Liu Be made himself as the emperor of Shu Han. In 229 A.D, Sun Quan too made himself as the emperor of Shu Han. Thus began a new period in China called the Three Kingdoms.
The Han Dynasty ruled for over two hundred years. Its rise and fall are all part of what makes China the country that it is today. Chinese civilization and culture owes a lot to the mighty Han Dynasty.