The Great Wall of China began construction in the 7th century BC, with various sections built by different states during the Warring States period. However, the most famous version of the Wall was constructed during the Ming Dynasty, starting in the 14th century and completed in the 17th century. The primary purpose of the Wall was to protect Chinese states and empires from invasions by nomadic tribes from the north. Over the centuries, different sections of the Wall have been built, rebuilt, and maintained, contributing to its complexity and significance as a UNESCO World Heritage site and a symbol of China's historical strength and ingenuity.