Qin Shihungdi was the first emperor of the Qin Dynasty in China. He ruled in the 200s BCE.
Shihuangdi did many things that altered Chinese culture and history. He instituted "legalism" as his dynasty's official ideology. This was the idea that the central government had to be strong so that they could control the people and prevent them from ruining society. In part because of this, he set up a centralized, bureaucratic state. This was a much more organized system of government than China had previously had. He created a single system of money for the empire and started to build roads connecting various parts of it. It was under his rule that the system of defenses that later became the Great Wall of China was started.