The Qin Dynasty was the first imperial dynasty of China, lasting from 221 to 206 BCE. It was founded by Qin Shi Huang, who unified various warring states and established a centralized government. The dynasty is known for its significant reforms, including standardizing weights, measures, and even the writing system across the empire. One of the most notable achievements of the Qin Dynasty is the construction of the Great Wall of China, which was built to protect against invasions. The dynasty also initiated the famous Terracotta Army, a collection of life-sized sculptures meant to accompany Qin Shi Huang in the afterlife.