The Great Wall of China began construction in the 7th century BC during the Warring States period, although significant building occurred later during the Qin Dynasty in the 3rd century BC. The wall's construction aimed to protect Chinese states from invasions by nomadic tribes. Over the centuries, various dynasties expanded and renovated the wall, culminating in the structure we recognize today. Spanning thousands of miles, the Great Wall symbolizes China’s historical efforts to defend its territory and unify its people. Its impressive length and engineering marvel reflect the dedication of numerous laborers over centuries of historical conflict and territorial expansion.