Under the leadership of Qin Shi Huang, then known as King Zheng, Qin's armies employed superior iron weaponry, well-disciplined soldiers, and strategic alliances to systematically defeat rival states. By 221 BCE, Qin had conquered all opposition, and King Zheng declared himself Qin Shi Huang, meaning "First Emperor of Qin." The discovery of the Terracotta Army on the 29th of March 1974 was a momentous archaeological find that shed light on ancient China's first emperor, Qin Shi Huang (r. 221–210 BCE).