Emperor Gao (256 – 195 BC), commonly known in China as Gaozu, personal name Liu Bang, was the first emperor of the Chinese Han Dynasty, ruling over China from 202 BC until 195 BC.
After defeating the Qin Empire, Liu Bang, as one of the rival leaders was awarded the Principality of Han (known as Hanzhong, modern Sicuan, Chongqing, and southern Shaanxi), while Xiang Yu, the King of Western Chu, actually realigned the territories of not only most parts of Qin but also the rebel states, controlling the territories of 19 principalities.
In Hanzhong, Liu Bang focused his efforts on developing agriculture methods and training an army, through which he reinforced his resource accumulation and military power. The next step he took was to fight Xiang Yu, the former ally now a rival to rule the country, launching a war now known as the Chu-Han War.
Although Xiang Yu was far superior in military ability to Liu Bang, he was at a political disadvantage. Xiang Yu kept defeating Liu in the battlefield, but each of his victories drove more people to support Liu. When Xiang Yu finally was defeated, he could not recover and committed suicide.
The war lasted five years (206-202BC) and ended with Liu Bang’s victory. Having defeated Xiang Yu, Liu proclaimed himself emperor and established the Han Dynasty in 202 BC and made Chang’an (present city of Xi’an) his capital city. Liu became historically known as Emperor Gao of Han.