In terms of both land and population, China is one of the largest countries in the world. China has been around for a long, long time, but it wasn't always the unified nation we recognize today.
Those seven states were locked in a constant battle for control of territory. The fighting amongst the states was so fierce that this period of Chinese history would eventually become known as the Warring States period.
Prince Zheng became King Zheng at the age of 13. He ruled with the help of a regent until he was 22, at which time he assumed full control of Qin. King Zheng soon set a course to conquer all six other states in an attempt to unite China under his .
King Zheng methodically took on the other states one at a time. Han was the first to fall, followed by Zhao, Wei, Chu, Yan, and Qi. After successfully conquering the other six states, King Zheng began to rule over a united China in 221 B.C. He declared himself Emperor of China, renaming himself Shi Huang, which means "first emperor."
As emperor, Qin Shi Huang made sweeping reforms to make China a truly united nation. He reorganized the government into administrative units and established a common currency, standard units of measure, and a standard way of writing. These reforms were necessary to prevent the conquered states from continuing to think of themselves as independent nations.
The new emperor also began to build the infrastructure of China and promote travel and trade by constructing a large network of roads and canals. He also solidified China's defense against northern invaders by beginning the Great Wall of China.
Despite these important reforms and improvements, Qin Shi Huang was considered a tyrant. He forbid most forms of religion, insisting instead that all loyalty would be to him and his government. He wanted China's history to start with his dynasty, so he even ordered nearly all books in existence to be burned!
Qin Shi Huang wasn't just concerned with ruling China during his lifetime, however. Due to numerous assassination attempts early in his rule, he became obsessed with searching for an elixir of immortality that would allow him to live forever.
Despite his fascination with immortality, he was also obsessed with the afterlife. During his lifetime, he had as many as 700,000 workers construct a tomb the size of a small city that was to be guarded in the afterlife by a life-sized army of over 8,000 terracotta warriors, horses, and chariots. The complex tomb was also supposedly protected by rivers of poisonous mercury.