秦始皇 (Qin Shi Huang) was the first emperor of a unified China, ruling from 221 to 210 BCE. He is known for founding the Qin Dynasty and implementing significant reforms, including standardizing weights, measures, and even the writing system across the empire. His reign marked the beginning of imperial China. One of his most famous achievements is the construction of the Great Wall of China, which was built to protect against invasions. Additionally, he is known for the Terracotta Army, a vast collection of life-sized sculptures created to accompany him in the afterlife.